As someone that has contacted Groupon before, I can tell you they are extremely responsive and usually are able to resolve the problem. According to their refund policy you can get a refund within the first 3 days of purchase and after that all sales are final. However, if you experience a problem with a business even after three days, I recommend reaching out to them to see if they will assist you with the refund. Visit their Refund Policy page for more details.