Incorrect billing

Month after month I am having billing problems with Telkom mobile. Its either they bill me too much or bill me wrong. Telkom mobiles billing system is so bad and irritating. Spend hours on the phone with them but they cant get their billing right. Last month they did not debit me and I only picked this up as I was going through my bank statement. I then decide I am going to pay them before my line gets suspended - the very next day my line was suspended after I send proof of payment to [Email Removed] I then spend another hour trying to unsuspend my line and it only got unsuspended the day thereafter. Today (15th) they debit my account for the money I already paid plus the money that is due the end of June 2015.