Can I return non-faulty goods?

If a product which we bought is consistent with the agreement (trousers are basically all right, but we seem to trigger outbursts of uncontrollable laughter of our friends every time we put them on), then it is left only to the vendor whether he or she accepts the product and gives us a refund. It is a frequent practice for stores to offer the possibility to return purchased goods within the term indicated by them (we have to keep the receipt, though).