Groupon SA
Promise of refund, now only credit to use again

I've asked for a refund 12/6/13 via phone, received a email to confirm they received my request. On 13/6/13 received a email to inform me that refund was made to my credit account. I made a call again, 13/6/13 to ask for a refund not credit. I received a email requesting my bank details, which I provided. On 20/6/13 I phoned and was informed that a email was sent, requesting the reference number of my purchase. I emailed the info 21/6/13. Today, 26/6/13 I receive an email informing me that I will not be refunded, but credited. They can't make a choice for me if I want my money refunded. I don't want to make use of their vouchers if this is the kind of service that they render.