Telkom - Extra Chargers

My account was debited for my monthly installment. But the debit came back reversed. When I called the agent of Telkom she told me that they will do another debit on the 16th of January and the account will be paid. Then told me to speak to my bank because she dont know. I don’t understand why but this is not my fault I didn’t debit the account and why must I pay extra to Telkom. There was money in my account. And further to this I have this contract for 2 years with no issues now when I sent through an email for upgrade I got an sms stating that you can’t do it because my account was not paid. Over the past 2 years there was no problem but now there is. How is this possible. I am going to lay a complaint with the ombudsman. Why should we pay. And its about + R200. For what am i been charged am I getting something extra.