Unhappy client

I'm so much disappointed with Cell C service. I wanted to change by banking details and try to contact Cell C. At first it was a struggle to get through telephonically, after several days of struggling I got through, only to be told that I need to make a direct deposit before they can change my bank details, by then the account qas already overdue with 2 payments. I decided to go to an Cell C outlet, only to be told I need to contact the call centre, the person that assisted me gave numbers that was not working. I went to try the call centre again, after several tries I got through to the call centre, after how long eventually someone that knew what she was doing gave me the banking details and a email address. I dud forward my bank details and made arrangements to pay the account. They decided that they want the balance of the contract outstanding to be settled. What a nightmare. If they changed my bank details as requested by me, they would've spare me all the trouble I went through and the account would have been up to date. I'm willing to pay the contract on my terms, if it was not for their staff incompetence non of this would have happened. I really need this nightmare to stop.