GROUPON BAD SERVICE

I have on 3 occasions used GROUPON and I have had no joy on any of these occasions . I recently purchased spa vouchers which I didn't get and was not reimbursed . I enquired on 3 occasions and on one of those occasions I was told that I will get the vouchers , did not happen, last occasion I was furious and the phone was slapped in my ear . I am so frustrated with them , it is not funny. I had dealt with daddysdeal and wikideals and have had no problems at all , in fact my vouchers was available within days of the EFT transfer being done , but with GROUPON this has not happened. Can someone at GROUPON please assist me .