Sync up scam device with T mobile

I won a sync up device at a car show and TmObile had a kiosk there , I spun the wheel and supposedly won a sync up device , they said it was free for 6 months and all I had to pay was 9dollars to get it hooked up, well I never got any paperwork and they didn’t tell me I had 14 days to return it.. meanwhile I never used it and found out it drains your car battery so I went to a store and tried to return it, it was past 14 days and they refused to help., I was billed 14 dollars on my bill and I called customer service they are no help … I’m a senior and they also lied about my original contract with them for my web and phone service I’m stuck with this device paying for it for 23 months…Help I’m stuck.. I wanted them to send me my original contract and they said they didn’t have it wow f——d up