MTN Billing Services are bad

My contract with MTN ended in May this year and i called in to to let MTN know that i wanted to close the contract. But every month after that my bank account had been debited and I reversed the funds with my bank . I have been getting letters that i owe MTN. I have tried a lot of times to call the customer care but non of them is able to help me , they let me hang on the line for 30 minutes and more, If I try to call again the I am unable to go through because i can not call more than twice to customer care in a month.<br> <br> Can some one please help me. I have been paying MTN R729 for 24months , I never skipped a payment and this is the kind of service i receive. Im really dissaponted in MTN.<br> <br> <br> <br>