He is not legally obliged to accept refunds unless the goods are faulty, not as described or not fit for the purpose.
If you bought a pair of trousers labelled 32" waist and they are actually a 40" waist, you are entitled to a full refund and any restocking fee would be unlawful.
If you bought a size small off the peg in the vague hope it would fit, and it doesn't, then the seller can refuse the refund.
So it very much depends on the circumstances.
If you bought the goods online, by post or over the telephone, the rules are very different.



