So if the brakes on your 7 year old car fail because of lack of maintenance, the manufacturer is supposed to cover the cost? From what I read about you L/T it likely had nothing to do with Dell the culprit was likely the load of Mcafee, since after uninstallation it worked. Welcome to the real world, any computer shop, not just Dell, would have charged for their time and any components installed, after all this is/was a 7 year old system.
Seven years ago I got my Dell Inspiron 1521 laptop with an embedded Dell/Sprint Mobile Broadband Minicard for internet connection (we live in a rural area with few options). It worked pretty well till last fall. Sprint said it was a Dell software problem. When I contacted Dell, it was difficult to get the technician to understand what my device was. Finally, he said to ship it to the Texas Repair Depot. About 3 weeks later they said they had replaced some parts and it was fixed. When I got it back - still no internet connection (nor ability to print - a secondary problem I reported). I got a new Sprint device - a USB connect stick. It didn't work. Finally, I uninstalled McAfee and voila - I had internet and printing back!
I figured that Dell owed me a refund of $179. After much discussion, they said no because they did replace two things that were faulty - some memory and the WLAN wireless network card. Now, I don't have a network nor a router - just the laptop, the connect device and a printer. But Dell insisted the WLAN card contributed to my USB connect stick working right. I'm not that computer savvy so I don't know.
It's like my car wasn't running and I brought it in for repair and they fixed a crack in the windshield but the car still didn't run. They're charging me for fixing the problems I reported to them when they did not fix them. In retrospect, I would not have sent the laptop to the Dell Repair Depot.