HIFIgo being sketchy with my friend

I havbe a buddy who bought a Topping L30 last year from hifigo. In leu of all the issues he requested a return. only a few issues. His unit does not have a S/N sticker only a QC sticker which is odd. they gave him the run around for a bit denying that his unit isn’t one that is affected. issues is he doesn’t know his SN number and they don’t so they can’t really prove anything. I then found an individual who managed to get a refund for a unit that also didn’t have a S/N. they are now asking him to provide a PR card. for us canadians who didn’t immigrate here this card has our social insurance number. if I’m wrong please correct me. but if I’m not wrong this is some sketchy shit.