We were one of those "people/couples" Carol. Years ago at Bliss when they had dining we didn't realize a service charge had been added so we tipped on top of that. We were staying at the Caravanserai so we did not drive. Too much sun, too many cocktails and well....
When we figured it out later the server or restaurant manager because who knows who gets the "service charge/tip" winded up with a 35% tip.
If there is 15% added we typically do not leave additional monies. There are of course exceptions.
As many has already stated...rings out my feelings exactly. I hate being told what I HAVE to leave for service/tip or whatever else they can call it. I always leave minimum 20 percent wherever we go....but.....when I am told what i MUST tip...i rarely will leave any extra!!! The exception is when service has gone above and beyond!!! The added service charge is a scam...we all know it and so do the restaurant personnell and management/owners. They are hoping that after a few drinks, people won't notice, or are first time ''virgins'' to the island, and will double dip the tip!! It's a win/win for them....they make out either way..sometimes double. In most other industries, a practice of deceit would be illegal. New mantra should be "Diners Beware".