Shocking Customer Service

I purchased a voucher on Groupon on 10 September 2015 and paid via EFT the same day. I kept checking for my voucher to be available each day and until 16 September, it was still processing. Then I checked on 17 September and the voucher was \missing". I immediately called to the call centre and was told that I hadn't in fact made payment. I have the proof of payment from my bank and all bank statements proving the payment to the value of R699.00 did go through. I demanded to speak to the team leader in charge and was put in touch with Seraaj who promised me everything would be sorted. I received a call from Seraaj on Monday"