I think the issue here is not that there is a problem with horsemeat, but that people have effectively been "missold" it as beef. How would you guarantee that the one you had contained horsemeat? As from all of the information i have seen, only select batches of the product contained horsemeat, not all of them. Have you kept all of the packets for this?

Out of curiosity - How was the metal piece there? Is it a display arm that you happened to catch at the wrong angle, or a sharp piece of metal? If the manager was informed, then there is a good chance they have already looked at the piece of metal themselves, and if it was a standard piece of kit, then they could argue that it was not dangerous. Unusual to find them only offering a partial refund and trying to keep the coat though.

Ive had issues with them in the past, and up until recently just tended to accept that they would be slow (same as maelstrom etc), so if i wanted it quickly, then i had to get it direct from gamesworkshop, or wait. Are there any other companies out there offering quicker dispatch?