Stll no refund after 10 days - SLA 3 days

On the 23 August 2015 I was supposed to pay R603 towards our DSTV account but mistakenly I paid R6033.00. I called the Call centre and was advised of the refund of R4825 as I have deducted R604 which is a payment for August and another R604 for September subscription. I was told to send an e-mail to Journalescalations which I did and received a reference number: ***. Until today I have not received my refund. Should I not receive my refund immediately I will start calculating interest which must be payable by Multichoice or I will take this matter further.