Second debit order in one week

I have had previous problems with Telkom/8ta but this time i am beyond fed-up. The beginning of the month (March 2015) my debit order went off for my monthly contract. After the debit order Telkom/8ta still suspended my phone line as according to them no payment was received, so after sending bank statements proving they debited my account it was reactivated. Then a few days later they went and debited almost double the amount from my account and no one from Telkom/8ta is able to tell me for what reason this was done or nor do they get back to you to explain as to when this funds will be refunded (as another bank statement proving the debit order was emailed) or who authorised a second debit order in the middle of the month as my agreement was only for the beginning of each month. I have not received any statements regarding this amount that needed to be debited. I can not understand why no one can tell me as to why this has happend. I am utmost disappointed and unhappy with the service that i am getting from Telkom/8ta.