Great price, good delivery, awful after-sales service

Bought a lens at a great price. Ordered on Monday, delivered by Friday; there was even a £10 bonus discount for ordering over the UK Bank Holiday and that's where the poor customer service appeared. The payment, through Paypal, didn't subtract the £10 offer, so I contacted SLR Hut immediately and they offered me a credit on a future purchase. I politely declined and asked for a refund, to which they agreed - seemingly perfect after-sales service I thought. However, when I hadn't had the refund a couple of weeks later, I asked if there was a problem and was told no and it would be hastened. Nothing for another week, so I politely asked again and was told it would be paid in 2-3 working days. 2-3 days later, still nothing; at this point I could see this was going nowhere quickly. The order was made on 1 May and I still haven't had a refund. It's only £10 I know, but it's my £10 and if their customer service is this bad for a simple request, I hate to imagine how difficult it's going to be if I ever need a warranty repair. Anyone can sell stuff cheap, half the internet is based on it, so good customer service is where the real value is and SLR Hut just doesn't have it. You have been warned.