Stole my Money Off Groupon

I bought a groupon voucher for a 2 night stay at Dolphin Crest Guesthouse and each time I tried to redeem my voucher I was either told to call later or forward the voucher and they'll get back to me or they just wouldn't answer the phone. I have called over 20 times to try make a booking or even get a refund but sadly no feedback. I also regret not reading the reviews of Dolphin Crest before purchasing the voucher as the reviews clearly warn people of how terrible the place is.I am highly dissatisfied with this experience and don't understand how a business like this is still allowed to operate.