2 weeks- no refund or response in 3 emails

I have booked a brazilian for my hair and when I phoned for an appointment the lady told me that the groupon was not a straightening but rather to remove fizz from your hair. So I asked groupon for a refund because I was under the impression that it was for a straightening session. I emailed groupon on 2 may 2015 asking for a refund and sent follow up emails up to today, without any response. I tried to phone the number provided but the line is so soft I cannot hear anything. I want my money back asap. The previous time I did a refund for a groupon voucher is was hastle free - I cannot understand their lack of communication now.