Still waiting on Refund after 2 weeks

I purchased a Groupon voucher on 29 Aug and paid the same day via EFT. a Week later and still no voucher received i phoned them to find out what's going on, only to be told that their system has rejected the payment. No Worries. I sent in my banking details and proof of payment for the refund. It is now the 14th Sept and I still haven't heard anything from anyone at Groupon. I have called 3 times and every time they just say it has been escalated.<br> Totally unacceptable service from Groupon. <br> <br> <br>