Online Payment - Double Charged and not willing to Refund me

On the 3rd of November, I tried paying for my DSTV subscription using the online payment method on the dstv site. The online payment transaction was said to have failed, and not being one to repeat failed exercises, I decided to rather pay at my local Checkers Hyper.

I thereafter on the 5th on November, notice that the online payment went through on the 4th of November, the day after my payment attempt. How can this be? I have been calling the MultiChoice customer centre for 3 days now , and even after sending them my bank statement, they are not clear in giving me my refund or even on how the online transaction could have gone out the day after I actually tried to pay. This is really a nuisance as I just want my money back.