wingco1,
My cousin is still in a contract with TT and managed to get the previous overpayments credited to his BB account via the TT forums - even that was a very, very slow thing to accomplish! Phoning TT support was a complete waste of time
I would imagine that if one left TT and went to another ISP then a refund on any overpayments made to TT could be rather difficult to get...
4M2.