Incorrect billing unresolved

Telkom has been billing me incorrectly for 2 months now. Last month I was charged a penalty fee because telkom decided to debit on the 24th of August whereas I receive my salary on the 25th. On the 25th there was money in the account and they didn't debit. Now I took a router for R139, which I received late last month and it only started working this month, I was billed twice for that. Could someone please attend to this matter, I'm a very upset customer.