T-Mobile T-Mobile sells used phones as new. Internet

T-Mobile sold me a "new" phone at one of their stores and gave me the rebate form for it. I got a letter telling me that a rebate was already given on that phone. That's when I found out they sold me a used phone and made me believe it was a new one. The customer service rep told me on the phone that she hears of this happening quite frequently. I sent in another rebate form for the 2nd phone they gave me when I returned the used one and then I got a letter saying that I don't qualify for the rebate because the data plan I signed up for doesn't cost enough. Nobody tells you this when they sell you the phone. Also, ever since I agreed to another two year contract in June my bill has been wrong and I've had to call their customer service to get it straightened out each month. I've been their customer for 10 years and this is the first time I've had problems.