As a fellow shroom lover, I DO feel your pain. Frankly, I couldn't imagine them doing something so asinine, so my apologies. If you go to a place where it's happened more than once, perhaps you should try explaining to them that if they give you a one topping you're going to PAY them for one, and that if they want to get paid for four they'd better give you that many. Or insist on seeing them make it, as you said (if only so you know it doesn't come with the saliva topping. ) And if it's delivered, well, sucks for the delivery guy (who, of course, didn't make the pizza and can't control the guy who did. )