I had sent my old device iPhone 6 Plus to Tmobile for a trade in credit. The tracking # showed Tmobile warehouse already received it but no credit was issued. I have been contacted customer service so many times and they said they didn't receive the

I am haveing an almost identical problem to this. I returned a phone to T-Mobile using the return label that came in the box when I received the phone. They claim they either can't find it or didn't get it? Did you ever get this resolved and if so, how?