Keep your receipts and check your credit card charge! If the bartenders don't feel that you tip them enough they will add extra tip for themselves even after you've signed (think: 25% top up). This was done on two separate occasions on my card. It is fraud and theft that could easily be brought up with the police. I had to dispute the charges through my CC company, went back to Mario's and asked them to produce the reprint of my signed copy and they said they could not find it. The manager, however, was nice and listened to my concerns and tried his best to help me, but did not seem keen on following up.