Yeah it sometimes happens if you break rules and don't respond to or don't get emails.
There was a big UK stockings/pantyhose/uniform site that dropped my percentage a while back because I was promoting on domains that had their site names in them.
They only dropped the low-earning ones and never touched a group of them that was making $xxxxx a year with them. A bit unfair I thought but I just slowly moved to other sponsors anyway and eventually stopped promoting them altogether, their loss as far as I'm concerned.
It's funny what you see when you have multiple accounts with the same sponsor
They've been laying off staff I heard recently as well.