I have a contract with Tmobile since 2005. I have often used call forwarding from my phone to the other phone when I am not available. However, this time I got a big bill from them for callwarding charge of 45 cents/min. I called and complained about the bill but they didn't take the overcharge off my bill. They said I only have 500 minutes I can use for my callforwarding. I asked them to show me where in the contract said that. They didn't have it but insisted it was in the contract and refused to take the charge off my bill. What should I do?