PATHETIC CELL C UNABLE TO CORRECT BILLING!

For the past 10 years I've had two contracts with CELL C. Two years ago I terminated a contract with CELL C ***). Even though the contract has run its course I still receive notifications from CELL C saying that I owe them money for the expired contract. The money was automatically deducted from my account. How is it possible that I could still owe CELL C money? I constantly receive notifications from MBD INC telephone ***. It is clear that loyalty to a company means nothing which means I will be aiming to terminate my existing contract as soon as possible. CELL C customer service is of the poorest I have encountered as this is not the first time I am attempting to have this resolved. I sincerely hope that a competent person exists within CELL C that will be able to resolve this asap.