Items not shipping despite being "in stock"?

I placed an order for a number of items on November 28 - all meant as Christmas presents. All but one of the items was listed, at the time, as "usually ships within 24 hours." I intentionally stayed way from anything that was listed as backordered, or as not shipping relatively quickly (aside from the one accessory which I could wait the supposed "3-5 weeks" they claimed it would take to ship.) The order was broken up into 2 parts - one consisting solely of the laptop computer I ordered, and the other consisting of the remaining 8 items, which were mostly Wii accessories & games. The laptop was estimated to arrive that week, and the rest was supposed to arrive December 15, which I figured was when the 3-5 week item was expected to get here.

Now, I admit, I tend to idly refresh status pages to see if there are updates whenever I have a few seconds (during commercial breaks, or when I have a lull work-wise), so imagine my surprise when both orders came up with an estimated delivery date of December 1! I love Christmas, and giving gifts is important to me, so I was very excited about receiving these items so I could wrap them up all pretty-like and put them under the tree.

December 1 comes, the laptop arrives as expected, and so does one of the 8 items from the other half of the order. This seems a little fishy to me, especially since the second "order" shows as being "In Production" still. So, I fire off a quick email to customer support, and make sure that the next day I listen for the door, just in case a package got delayed. December 2 comes, and one more item arrives - a game that requires the other wii accessories I ordered in order to play it. Ok, no problem, I'll just wrap it up and put it under the tree, the rest should be here soon, right? December 3, I still haven't heard back from Dell regarding my order, it's 2 days past the estimated delivery date, and the status still shows as "In Production." I haven't even received an email to say "we will respond to your email as soon as we can."

Fast forward to December 5 - I finally get the "we will respond to your message asap" email - 4 days after initial contact. And then, it's 2 more days before I get a response. I'm not happy with the reply - that all six items that I haven't received are backordered, but they claim that I will receive them by December 24, and that's all that matters. Of course, I was never informed via email or phone that these items were on backorder until after I contacted them, but I figure, they're telling me now, it's no big deal.

December 12 - I'm checking the site, to see if maybe the items I ordered are back in stock and, sure enough, they are all (except the 3-5 week item) listed as "usually ships within 24 hours." Great! I should be getting mine soon, right? The next day, however, I FINALLY get an email saying that one of the items on the list (just one, mind you) is backordered, and is estimated to arrive on January 5. Ok, fine, it's one item, but the rest should ship soon, right? Worried, I send another message to customer support. This time, I get the "we will respond to your message" email the same day, but it still takes 2 days to get a reply. Oh well, no big deal. I open the email, expecting to find "xxx, yyy, and zzz have shipped and are expected to arrive on december xx," but instead, I'm informed that ALL of my remaining items are, once again, on backorder, and expected to arrive on or before January 5. Their excuse is...
I would like to inform you that, since this is not a Dell manufactured item, we do not have a direct control over its production and supply. Most of our orders are delivered to our customers within the time frame referenced at the point of sale. However, such orders, at times, get delayed as they are unavailable from the vendor due to the demand supply gap. Please be informed that Dell Notification team always reaches out to customers (through phone or e-mail) to inform them about the updated delivery dates in case the orders get delayed. We are making all efforts to ship your order at the earliest.

Now, I can understand the hassles of dealing with suppliers, but at the same time, I have to wonder... How is it that a company so centered on technology can't keep track of how many of an item they have available to them? Other major retailers manage just fine, even if it's just telling you, when you try to place the order, that "oops, this item appears to be out of stock." Most of them even have a running tally on the page when they run low on an item, so you know "Hey, there's only 10 left, if I want it, I need to get it soon!"

Secondly, how is it that an item can display as being on backorder for 2 weeks and then show as shipping within 24 hours... and not ship to people who are already waiting in line for it? Did contacting customer service to begin with put me on a naughty list of some sort where everyone else's orders, even new ones, automatically get priority over mine? These were Christmas presents, ordered almost a month in advance. I do not have the cash this close to Christmas to go out and buy the items from Walmart or wherever if I was to cancel the order, and my account has already been charged for these, which means I'm already being charged interest on items that have not yet been shipped.

Third, if this is the second time they have been on backorder, why have I only received one email saying so, why did it only list one item, and why did it take Dell 2 weeks to send said email?

And, finally, why does my order status still have an estimated delivery date of December 1 despite it being December 14, and the order still being listed as "In Production"?

I've been a Dell customer for years, and have NEVER had problems like this before. At this rate, however, I'm questioning whether I will continue to shop here, or if I should take my money elsewhere.