Unallocated payment- 2 months later

I installed my DSTV decoder on 17 July 2015 and made my 1st payment cash at a Pick and Pay. Since my customer account number didn't work, I used my ID as reference. I emailed the proof of payment to be allocated, called the call centre, have personally sent the proof of payment to 5 different individuals who all escalated my request to finance and to date 2 months later my payment has still not been allocated. To make it better, this amount was again deducted in my debit order payment at the end of July 2015. Can somebody please help me???<br>