Back when this outfit was called Dixons, I made the mistake of allowing these guys to 'fix' a brand-new Walkman.
Every time it went away, it was gone for four weeks and came back (still) broken. Eventually (after seven months without the unit), I decided I'd had enough and asked for my money back - to which the store had the cheek of offering me half its new value on the basis 'it was now second-hand and more than half a year old''!!!
After a discussion with the store manager, I did eventually get all my money back. I think they have improved since then, although this article suggests this is not always the case.