T-Mobile(CHEATER) rebate problem

I have change to T-Mobile on Dec 2006 with rebate plan of $50.00, after that I have send all the documents to them on time. but I have received standard letter from T-Mobile (CHEATER) that your 10- digit wireless number is not in our system. I have called them and try to resolve the issue, they said you should get your rebate in six weeks and guess what? I got another letter with anouther information is not maching so we can not process your request, again I called, they said ok now you should get your rebate in six week and guess what... after six week again I got same letter as 1st letter again. now they (CHEATER) said your rebate has expired and now system will not allow us to do anything and YOU WILL NOT RECEIVE YOUR REBATE. I talk with supervisor but no change in answer. Its just matter of 50$ but this CHEATER may be making millions by this kind of problem.

is there any way I can teach them lesson? or let their CEO know about this cheat business going on behind the door.

Thanks,

Sudhir Modi