my nephew had a defective samsung phone through AT&T - he is on my friends and family plan. The phone never worked well, and he was constantly talking to AT&T's technical service.
Finally, they told him they would send him a new phone and he could return his defective phone in the same box. He was told the warranty would apply as long as the phone was undamaged. Roughly 2 weeks after he had exchanged phones, he gets a notice that says AT&T has deemed his phone to be damaged. The only "damage" to the phone was a very small cosmetic blemish.
He offered to return the new phone they sent as he doesn't have $400 to pay full price for a phone, but they say that's impossible since he's used the new phone - basically he's screwed. Their process leaves the consumer completely powerless and makes the warranty essentially worthless
Product or Service Mentioned: Att Phone Service.
Monetary Loss: $400.