And what if the provider believes he deserves his full fee? Do you pursue an argument? Do you risk having the provider post your personal information? I recently had this situation with a WELL REVIEWED provider here who showed up (my place) under the influence. I'd seen him before; regardless, I should have tossed him out but didn't. When he couldn't perform, I got up but insisted he sleep it off before driving. I had payment in an envelope on the table with his name on it (giving him the choice of fairness.) He took it. Providers can't be trusted to fairly evaluate their performance... they want their cash.