Shocking Groupon Customer Services

I recently purchased a Groupon for canvas prints (21 Dec 2015) when I received the voucher within 5 minutes, I realised I had bough the wrong size and immediately emailed the customer services team to please cancel the Groupon purchase and reimburse me the money I had literally spent the same day. I received a ticket number and email stating that I would be contacted in 2 working days.. it is now 2 weeks and still nothing!! no call, no email, no resolution. I have also tried calling the call centre - what a joke.. the same recording playing over and over again. press 1 for customer service - it goes back to the start menu. you hold on, and the call cuts. Please can someone from Groupon contact me immediately and solve this issue!