After getting bad service I am thinking about refusing to tip.
How did you get bad service?
I don't like it when my waiter is incompetent while I am out eating.
There is nothing wrong with not tipping if you got bad service from someone. It will teach them a lesson and hopefully they'll learn from it.
Yeah and I think the waiter discriminated against me too with how he was treating me.
If you believe that the server discriminated you then you'd be right to not tip. Hopefully they understand why and learn how to not discriminate against others.