Incorrect billing information

I logged onto my account only to find out my account is in arrears? You tell me how this is possible when my debit order was processed on the 20th of Feb and the money left my account on the 22nd of Feb. To make matters worse, my bill is about R300 overcharged? Why? I cant find out because your call centre line 082 111 keeps cutting the call before I even get to speak to a consultant. Also your chat facility is not working and your bill online is not yet updated. How can you call this customer service, when you are not servicing me as a customer through any one of your channels. I expect an answer today!!!