Account still being debited

I had a contract with netstar for three years. My contract finished in May this year. My account was all upto date. My account still being debited. Can someone please explain what is going on. I spoke to a consultant yesterday. The consultant tells me the account is stil active. What happens is when a contract expires you should receive a callfrom the company asking to renew a contract. But nobody called me. I spoke to a consultant in May and I paid all that was outstanding. She said I'm calling you back in five minutes. WAITING KAISHA.... Terrible service.. Their consultants are not trained well. They need professional training.. I need this debit order removed immediately...