Horrible Customer Service Experience with Dell

The following is a summary of my harrowing customer service experience with your support staff in spite of purchasing Premium Warranty:
1. My ordeal starts when after spending over an hour on the phone with your customer service personnel they finally send a Technician down to replace the monitor on my Dell XPS 15 L521X on 1/24. As soon as he left I noticed that my laptop would not boot up anymore and would keep getting stuck at the Dell logo screen and would only go through if you repeated the process 5-6 times (a problem that I had never experienced before) so I called him within 5 minutes and he said that there was nothing he could do and that I should call Dell support.
2. I emailed support several times during that week only to get the standard call us line. I was reluctant to waste another couple of hours on the phone so I tried everything for a week including updating the BIOS and changing the boot settings to no avail. Finally, I had to cave in and give them a call and of course more than an hour later they realized that it’s not the BIOS or the windows installation etc. (despite my telling them so!) and they agreed to send a technician down to replace my motherboard and hard drive. I specifically requested them to not send the same guy because it was after his servicing that the problem arose but they did indeed send him again. Also, despite my express concerns about replacing my motherboard and hard drive with the exact configurations I originally had, I was disappointed yet again on that front too.
3. So on 2/6 this same technician replaces my motherboard and hard drive and leaves right in the middle of windows 7 installations and now the real nightmare begins! As soon as windows reinstalled (which took just another 10 more minutes which the Dell technician couldn’t spare) it got stuck on the Dell boot logo again! I called my case manager as soon as I found out (who never got back to me). In the meantime while I waited for my case manager to get back to me I checked my system configuration and I was shocked to see that instead of the 16gig RAM that I used to have I now had only 8 gig! So yet again I called the support line and after consuming yet another hour of my time I was asked to ship it to the Depot. Not only I had 8 gigs less RAM my NVIDIA GeForce GT 640M (2 gigs) graphics card was also missing (probably the new motherboard never came with the card which was included in my original configuration).
4. On 2/8 I ship my laptop to the Depot in the box provided which they received on 2/10 and immediately upon receiving my laptop was placed under Billable Hold. I was never informed of this but luckily I was keeping a track of the status online since I learnt to be skeptical of Dell service at every step of the way. So I have to contact customer service again spend another half hour asking them why has been put on a hold and they try to placate me by saying that they don’t know so they would be emailing the Depot (talk about communication gap!).
5. However, given my harrowing experience so far I decided that it was time that I email Mr. Michael Dell about the hoops I have had to jump through (and sadly I continue to have to) to get any service or meaningful communication at all from customer support ! And next morning I get a very patronizing and incredulous phone call from Abhishek G, who is a member of your “Executive Customer Support Team” who first of all wanted to verify whether I indeed had 16 gigs of RAM to begin with (I in fact happen to have screenshots to prove it which I emailed over to him but haven’t heard a word from him since) and then promised to get back to me within two days.
6. Two days later I am assured that my laptop is sent back to me fixed with 16 gigs RAM and the Nvidia card. On 2/14 I receive my laptop (with the RAM, heat sink, motherboard, hard drive and windows installation replaced) and press the start button only to find that the boot problem still persists! The laptop still gets stuck on the Dell Screen and has to be repeatedly turned on and off to finally get to windows (Please refer to my video for proof). I am not sure how your certified technician's "extensive testing" could have missed my primary problem that is so simple to check if it has been fixed or not (by just pressing the power button and turning the laptop on)!
Your technicians have tried to fix my laptop a sum total of three times now. I have spent several hours on the phone or emailing your support staff and several days without my laptop only to have it back unrepaired from your Depot. The hard drive, motherboard and windows have been replaced twice and this time round even the heat sink was replaced but none of this seems to repair the boot problem.