My refund from Telkom

I am fairly new with Telkom so in August was my first month of paying premiums. I noticed that they did not deduct on my requested debit date so I made a deposit directly to their bank. On the 31st August they deducted my account with the R1664. 57 that I already paid and they have been giving me the runaround ever since I asked them to refund me back. They credited my bill after I told them I don't want a credit on my bill. Yesterday they paid out R730+ and they're still trying me stories about the remaining balance. They still owe me R399.00 from July, that was meant to be a test debit fee and I am very angry and disappointed with their service.