Still waiting for refund

Good day, I've ordered a dash cam from Groupon. It was delivered and goods was damaged. The courier company came to fetch the damaged goods. Groupon sent me notification that they have received goods. Its nie than a month later and im still waiting for my refund to be made. Ive sent all documents and bank details 3 times already and nothing. Don't know what to do anymore as they don't get back to me.