Telkom **** billing department!!!!

I'm so ****ed off with telkom and their **** billing system. A while ago I've have had a few issues with telkom deducting from my account. So I spoke to them and they said that if I do a direct payment atleast 7 days before they won't do a debit order because my account should be in credit . So I do my payments of R1300 on the 23rd of November(my debit date is 31st) and I wake up this morning to see that my account has been debited with R830. Now what really ****es me off is when I view my amount owed to telkom. It states that I am R1300 in credit with them. So now I have to go on till month end with about R500 because of their **** billing department that can easily just take your money but then you have to wait 2 weeks to get it back. Oh yes, not to mention that this has happened before 2 months ago and I've had numerous issues with this ****.