AT&T to Unlock Off-Contract iPhones

To quote T-Mo:

If you paid full retail price for a device, you qualify to have the SIM subsidy unlock code provided if you meet the following requirements:
The device must have been purchased at a T-Mobile retail store or authorized T-Mobile retailer.
The device must be paid for completely. You must be able to fax the proof of purchase to T-Mobile.
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Now I bought my Amaze 4G in a T-Mo store without subsidy last November, on Black Friday, but I don't think I still have the receipt for it. I am on a prepaid 4G plan in good standing and I don't see why I have to go through all those hoops to get my phone unlocked. That whole faxing thing reminds me the conditions of those stupid mail-in rebates that are obviously aimed to stop people to actually avail themselves with it.