The Real Hennies, is this a clever **** to make more money?

On a recent lunch at this establishment in Port Elizabeth. When the bill came we noticed that they had added a 10% SERVICE FEE before showing the Amount due. Underneath the waiter had written TIP before circling an empty space which the customer must fill in. Meaning that over and above the service fee a tip could still be added. I asked the waiter about this and he explained that they did not receive a wage and that 10% of the service fee goes to the kitchen and 10% goes to the bar. The 80% that is left would then be his wage. A tip would be the extra but not considered part of his wages. He said if I wanted I could not tip. However if what he is telling me is the truth then of course he would miss out on a tip he would otherwise get, and who wants to look like a cheapskate in front of a waiter? But the whole thing is very disconcerting. I would like to find out if indeed the waiters at The Real Hennies do not get wages because I think that this would be against South African Law which stipulates that waiters must be paid a minimum of R28.76 per hour. Personally, I always tip 10% but when I now am forced to pay over and above another 10% I feel I'm being taken for a ride. I for one would start to avoid going to The Real Hennies.