You may want to just see if the CSR can help you before you begin with your impolite manner.
It is a form of abuse to act like this way to someone who has to take it. If you were in public, you could very well by cited for disorderly conduct. Perhaps the laws need to change.
Everyone now knows that there was the possibility of your food being spit on in the kitchen by the waitress when you were rude to her. Keep in mind CSR's have some lee-way on how your situation will be resolved.
Be impolite and you may win the argument; but you may not get the best resolution.