Verizon Wireless fradulent billing Albany New York

First my contract expired, so I called to cancel. I paid my last bill, later they sent me a cheek due to an overpayment. Almost two months after the fact I recieve another bill, now stating that I owe twice as much. This is enough information on grounds that verizon wireless has a jacked up billing system. I also was getting billed for a phone number that I did not sign up for, but I paid this anyway just to get rid of the contract. I guess it is thier way of a non-judicial form of punishment for switching carriers.

James
owosso, Michigan
U.S.A.