T MOBILE tmobile accepted my return box and signed for it and claim they did not get my phones ( LIARS!) fort worth Texas

HI First i posted on tmobile site this and the admin team deleted it , i now posted it again , on tmobile and bbb now here , please read my problem with tmobile , I ordered the upgrades 2 iphone 5's(via online support) and decided I wanted the samsung note 2's, I returned the both the iphone 5's on the same day I received them 15th of april via USPS EXPRESS MAIL OVERNIGHT and I packaged it personally at the USPS store and mailed it from there , reason is because tmobile never included a return shipping label ! I shipped the 2x iphone 5's to the T-mobile warehouse two weeks ago (tracking number confirmed it) yet after repeated calls over two weeks they kept saying it was returned but not processed, and this could take up to 30 days. (When I first called they said it would e a very quick turn around of a day or so!) spoke to multiple supervisors and they have attempted escalating for handset research team 4 times and every time my email gets a response saying that they have not received any devices , LIERS! Yesterday I got a call from tmobile executive office due to my post on BBB and the lady I spoke to said " how do we know you sent us the phones ?" to which I said its been signed for by your employees and I have tracking to prove it , at which point she stated that she " tried to look for the imei and no phones , how do I know you did not send us an empty box or a box with cookies " ARE YOU SERIOUS ???? I packaged these phones infront of a clerk at USPS store and they physically weighed the package and placed postage on it. T-mobile is saying they received the package but that the phone's are not in it! I physically packaged it myself (Furthermore, it took two weeks for Tmobile to decide the 2 (two) $600 iphone 5's are not included? No way.) AND they even say the phone's were never used (which isn't true...I used them for 1 hour and I had the activated through phone support that same day so even this record keeping is wrong). T-moile says to contact USPS but this is NOT a USPS issue...USPS successfully delivered it, Tmobile received it, and then the Tmobile warehouse lost it or messed up the order somehow, and Tmobile is billing me for the phones that I can't even use, I Paid $656 up front for the two devices and they want to bill me for the remainder owed $600 for the two phones and the have the devices at their warehouse, luckily I have the two imei numbers and I will be reporting two phones stolen by employees of tmobile at the return warehouse if I don't see a return or my phones found at that warehouse ! I've heard others have had problems with the warehouse losng phones or messing up the orders...does anyone have any advice? I've loved T-mobile but I NEVER had a problem of this magnitude with AT&T I am intensely frustrated as I've been worrking on this for 3 weeks with NO solutions on the horizon, yet the bills are certainly being managed on time. And yes, all future orders I will do in the store, but I am not paying $600 for the phones their warehouse lost furthermore I want a refund of the 656$ that I spent on them . Yes, I bought extra insurance but USPS is not going to cover something Tmobile lost---nor should they.