Telkom mobile has done it again

After debiting my account with double the amount last month, I was told after I had to phone Telkom that the overpaid amount will lie as a credit on my account and I will not be debited again for this month. Sadly, last night Telkom tried to debit another amount of R303,90 from my account but it was returned due to insufficient funds. What the hell is going on???!!!! This is the 3rd complaint I am writing this month on hellopeter but no one has gotten back to me. I am really tired of this and as a client I demand that you fix this otherwise I am taking legal action!!!!