I went in mid February with three friends. We had...

I went in mid February with three friends. We had a great time. Our check was for $67.00 which I used my Amex to pay the bill, then I collected $5.00 each to give the waitress a twenty dollar tip. A generous gratuity for sure. Several days later I noticed an additional "unauthorized" charge on my Amex for $13. I spoke withe Adel the manager who explain that it was probably the gratuity their establishment normally adds. I asked why weren't we told as they were no signage, notice on the menu or mention by the wait staff to expect a separate charge on one's bill. I's been several months of contacting Adele, the manager, who promises to reaccredit my account. Hasn't happen yet. Granted it's not a lot of money but given the principle of the matter I think customers should be informed. I wonder how many other uninformed patrons have their credit cards charged in this covert manner, and for how many years?. By Rafael