Mailing it in, some with reason, some without

So I'm trying to find out when I "bought" a Motorola HS850 Bluetooth headset from CompUSA. I put bought in scare quotes above because I actually received it as a replacement for a Jabra headset whose battery had pooped out that had gone off the market and that I had, for some reason, bought the super deluxe extended warranty. So they said, here, you can have this one instead. Worked for me. And, my financial situation being far graver than when I purchased the original headset, I passed on the SDEW. Not that it may have mattered.
You see, that whole thing was an example of great customer service, because the original purchase was something like 30 months in the past, and if the original receipt still existed, I had no clue where it was. So I called, and a very nice person at the store in Virginia said they could look up the transaction at the store in Arkansas and print me out a duplicate receipt to use to get a new headset.
Today, everything is different. The Alexandria, Va. store where I "bought" the new headset is closing, along with a ton of others, and the manager couldn't be bothered to do more than tell me to call Columbia, Md. (And I can totally see that--I mean, he's screwed even more than when he was trying to get a good work effort out of people whose job prospects led them to CompUSA.) Columbia said it couldn't look up another store's receipts. The national 800 number was apparently designed by people who wanted to talk to anyone but a regular everyday customer, because there wasn't an option for anyone not on the Technology Assistance Plan, a Corporate Customer, interested in training, or some combination thereof.
On the other hand, Motorola is at least being nicely inquisitive about the situation. We'll see how that goes. And I can get a new one for under $40 on Amazon, but I hate buying things that are still under warranty.