Am I forced to tip your staff members?

While at Netcare Parklane a friend and I experienced pretty slow and bad service. <br> I didn't care for it much about this, as in such cases I just choose not to tip the person (her name is Phindile). <br> Our menus arrived after other patrons who had arrived after us.<br> We ordered smoothies which arrived 15 minutes after our food only after we asked where they were(which makes me believe they were ready but the Phindile didn't go look at them. <br> My daughter was sick and vomited and Phindile was no one to be seen another stuff member ( Phumza Mayongo) at the hospital brought me a paper towel. <br> After I came back from cleaning my daughter I asked for the bill . That's when I experienced the worst kind of self entitlement I have seen from a person. Phindile asked how much her tip was from the bill, I told her I wasn't tipping her because she had given us a bad service. She then said next time we want to eat there and not want to tip we must rather buy take-aways because that's how they make money. She made every excuses about everything which means she knew and was conscious of the fact that she had given us a bad service. She then stormed without giving me my card and slip