Faulty goods - no refund

I purchased an item and it didn't work, arranged collection and they sent out an alternative product as a replacement and that item didn't work either. I asked for a full refund as it was within 7 days and the customer service gentleman is unwilling to issue out a refund. I am still waiting for my refund and have no product either as I returned it. I let them know it's part of consumer rights to request a full refund however it fell on deaf ears. Absolutely appalled by the service or lack of.