I wouldnt have left it with manager, Id have stayed there until at least you got written proof that they accept what happened and are looking into it.

I worked at sainsburys as a student, some poor guy used the jet wash just after the chemicals were topped up. They werent diluted at all. Stripped the paint straight off his car. All he got was £150, which was his excess on his insurance to get a respray. I think he accepted it too! I wouldve gone fooking ape!