PC desktop ordering difficulties

I'm a long time Dell computer purchaser and user. I recently purchased a replacement Desktop for my aging XPS 8930 desktop, and had settled on the Dell Tower Plus EBT2250 ($2,948).

1. I had difficulty ordering/building a desktop with 2Tb of SSD drive within my price limit

2. So, I ordered the Dell Tower Plus EBT2250 and immediately rang to ask for another 1Tb SSD card to be installed

3. After some extensive comms I learnt this extra 1Tb SSD could not be added to the Dell Tower Plus EBT2250 before dispatch - this negative is inefficient and silly. I mean why not?

4. OK, so I then ordered another 1Tb SSD to install myself which arrived in good time (without the required m.2 standoff screw).

5. I went to install this morning and found the little m.2 standoff screw was missing

6. I live remotely so I rang Dell to order one (and another delay). I was told that the part would cost me $0.16c and the postage and handling would cost $17.06 

I mean, why wouldn't Dell just send it gratis after the muck about?

I could go into any computer shop and probably get one gratis, but the nearest is 300km away.

It's all very tacky and it could have been simpler if I had the build option to add an extra 1Tb SSD in the first place.

It's not the money, it's the muck around, and it's avoiding the muck around that brings me to Dell regularly since 2006.

If asked if I would recommend Dell again, I wouldn't be so forthcoming as I've been in the past. Maybe I'm just ignorant of the business complexities these days.

What could I have done better, other than to pay another ~$1,500 to get the 2Tb SSD and all the other upgrades as well that came with that option (and which I don't need)?