wireless fulfillment center I was cheated by their sales person & not responsibly to cover my lost NYC New York

The sales person Danielle (from Wireless Fulfillment Center, T-Mobile’s Authorized agent) came to me (to the store where I worked in NYC, NY) on 11/25/2016 to promote the “T-Mobile Black Friday Free iPhone 7 promotion”.  Danielle told me that if I transfer my cell phone service from Verizon to T-Mobile today, I can get a FREE iPhone 7 (or Samsung S7 Edge) for each line under my account.  I said to her that “This is too good to be true.  I don’t have to do anything except transfer my cell phone service to T-Mobile then I can get

a free iPhone 7 for each line (total 4 lines)”.  I kept on asking Danielle the same question over and over, and Danielle said: “YES”. So I signed the contract with Danielle.  On the contract, she wrote “Free IPhone 7 Promo” on it. A few days later, I received 4 new phones (3 iPhone + 1 Samsung S7 Edge) and ported my numbers from Verizon to T-Mobile.  In my mind that “this is it”, & I got this wonderful deal.  But after I received my 1^st bill from T-Mobile, I was charged by those 4 phones I got.   I called T-Mobile and the rep. told me

that I had to trade-in iPhones to qualify the promotion.  During the sales on 11/25/2016, Danielle didn’t mention anything about the trade-in.   So I called Wireless Fulfillment Center on 1/3/2017, the customer service rep. told me that “I can trade-in any phone to qualify it”. The gentleman also said that “if T-Mobile has any problem with it, T-Mobile can call him back to confirm it”. So I did the trade-in with the instructions from that customer service rep.   In the following months, I was struggling by calling between T-Mobile’s solution center and

Wireless Fulfillment Center back and forth to try to resolve this problem myself, but I got no conclusion.  During those period of time, nobody said anything about “I wasn’t qualified for this FREE iPhone promo. Closer to the recent time, I got different answers and reasons each time I called.  Those different answers all sounded to me that they were trying to find some reason to deny my qualification for the promotion.    To make a long story short: T-Mobile denied my qualification to get the promotion.   I called Wireless Fulfillment Center back on

5/22/2017 and 6/12/2017 but the answers were the same: “The sales person entering the wrong info on my account so I was not qualified for that promotion.  The customer service rep. also provided me the wrong info for the trade-in on 1/3/2017. At this moment, it was too late to fix this issue, and we couldn’t do anything to help me.”    I trusted the sales person’s words to sign the contract and followed the instructions from the customer service rep. to do the trade-in and now I’m stuck with paying 4 new phones ($2669.97) which

wasn’t in my budget.  Wireless Fulfillment Center now said: “Sorry, those people made a mistake and we cannot help you”!    Does Wireless Fulfillment Center shall verifying the information of my new account after the sales person sent in the request?  If I was not qualified for the promo, why didn’t they refuse me right at the beginning?  Why did the mistakes their employees made but I have to be punished, suffering, and stuck into the extra $ which I didn’t have to pay originally?