T-mobile UNFAIR BILLING - PAYING FOR A PHONE LINE NOT ON MY ACCOUNT Internet

 I had been with Tmobile for 4 years I had 2 phone lines and had the family share plan which ran me 150.00 a month for both phones. On Dec 22nd, 2011, My husbands contract was up on his phone and he did not want to stay with Tmob. He got another phone and ported his number out. We got our Dec bill and paid it for both lines. This month, I should have been billed for only 1 phone so when I got my bill, I was a little taken back because the bill was for 155.00 for 1 line. I called Tmob and was transferred to a customer specialist. She told me because I did not call and tell them that my husband was leaving that it was my fault. She then said that she could credit back that amount and then switch me to another plan, but that would extend my contract for another 2 years. We don't want that to happen, my contract ends on  the 15th of this month. So basically, I have to pay for a phone that is not working and I am not using or get locked into another contract. Its wonderful throwing money away. I promise to tell as many people as possible to never go with Tmob.. and I call it Tmob because it acts just like the mob, taking people's money and doing what they feel like even if its illegal.