I invited a caterer I found on Yelp to cater an event. Some of the food was great, some not so much. The caterer agreed to return $100, as it was clear that what was promised was not completely fulfilled. My attention was elsewhere when they left, and I did not get a chance to tip the servers (who did a great job!). I asked the owner to give our refund to his staff, so if any of you are reading this, ask your boss about it.