Tmobile activated a line with no permission, and have not refunded me.

I'm not surprised. T Mobile customer service is HORRIBLE. I second the suggestion to contact BBB. I just contacted BBB last night and put in a claim against T mobile. they screwed me over big time. T-Mobile had a very deceptive sales process with me, taking $700 from me. They convinced me to switch to Verizon (after 20 years of being a Verizon customer) by offering a promotion where I got an ~$800 credit for my old phone applied to a new phone, essentially getting the new phone for free. The credit would be applied monthly for the next 24 months. I then saw my bill and the credit was NOT applied. I called and they said they only gave me $75 credit, not $800, because my phone had a small crack on the screen. The salesperson NEVER told me the screen had to be flawless. I don't even remember there being a crack either. T Mobile never called me, emailed me, or mailed me about this. I found out about it from noticing my bill was too high. I contacted customer service and they claimed there was nothing they could do about it. I was lied to and cheated out of over $700.