WARNING! Don't use the AT&T mail-in trade service for your device!!

Just need to let everyonhe know what a scam AT&T is pulling.  I traded my iphone5s with the buyback program when I signed up for AT&T Next.  The guy on the phone at AT&T told me they were offering $300 on iphone 5s so this would cover my next 10 payments on the new phone.  Sounded great, and since our AT&T stores were swamped in December and didn't want to spend an hour in line, I opted for the mail-in program.  Got the confirmation email, all looked good.  Followed the Shipping instructions that printed on their shipping label sent with my confirmation email.  Mailed it in December, and they still have not received it.  The printed shipping instructions DO NOT say anything about tracking or insurance, yet it's their label that they send you to use when mailing your phone.  There is a tiny line that prints on the other page (not with the shipping label that you print) that mentions tracking and insurance are not included.  The print, however, is way smaller than all the other print on the page.  And it is not mentioned on the actual page that prints with the shipping instructions.  You would think that if they were concerned about operating a trustworthy system, they would mention that in the shipping instructions.  HERE IS THE CATCH:  The phones that come into the warehouse (this is not actually AT&T receiving the phones, but some contractor) that do not have tracking and insurance just never get processed.  This is their answer: "We have been very busy since the iphone 6 release, so we will excalate your case".  Yea, I'm on my second "escalation", and it's now March.  Plus, I got smart when mailing my husband's iphone 5s a few eeks later, sent it WITH TRACKING and INSURANCE.  Guess What??  We received his $300 promo card 2 weeks ago.  I have had 15 emails back and forth with a customer care rep, which has been nothing but a waste of time also.  I was last told by someone at the buyback contractor that I need to just call AT&T customer service and threaten to cancel my AT&T account unless I get the credit.  WOW.