GM telling us we WILL be terminated if we accept tips. Period.

I'm a barista, for context. But, we're being told that if a guest insists, to put it in the drawer (ie just give it to Target), or else be terminated. Can they override this extremely clear policy that took me less than 20 seconds to pull up? And yes, we showed the GM this, and we were told, very plainly, that what the GM says, goes.