CHARGED DOUBLE!!!

On the 30th of November, my debit was set to go off from my account of 497. Unfortunately, it declined because I didn't have enough funds in the account so I made a manual payment to telkom on the 16 of December for R907 because i wanted to cover the December bill and on the 18th, I had money come in the account and telkom deducted R906 which means they charged me twice. The amount reflected on my account but not the other account now I don't know what to do. I'm being told to wait till my next billing cycle which is ridiculous. That is a lot of money and I need those funds, I need telkom to refund me back my money.