advice re bank loosing refund

katykitten

my 18yr old son banks with natwest, in november last year he purchased some speakers on line from a german company - he changed his mind and told them he wanted a different model at a different price. The company told him they hadnt deducted the cost of the original speakers from his account and would go ahead and deduct for the second choice. My son then got a statement saying that the co had deducted both amounts, nat west say that its up to the co to refund him and the co say that they have - it seems like the refund is lost somewhere in banking cyberspace (its £123). He is no living in canada and communications are difficult - they wont deal with me of course. Were about to give up on this as we have reached stalemate with both parties saying the other is responsible......help!!