When I was the assistant manager of a Convenience store back in the 80s, I threw several people off the premises for being rude to our employees. I almost always was respectful as I told them to leave, but I would make it clear to them I would not allow them to raise their voice or curse at one of our employees.
Many of them would apologize on the spot, and continued to come in for years afterwards. What was funny is when they would get this apprehensive look and ask if they were permanently banned. I never told anyone they could NEVER come back, but then I never had any repeat offenders. The most memorable one was a guy who had bounced a check. We wouldn't let him buy gas (he was on empty) until he paid the bad check.
He was furious! He called the cashier and me every name in the book, and I told him to get his ass out of the store (those words). He asked to speak with the manager. Since our manager had recently quit, I was the manager and told him so. He was SOOO pissed. Three days later he was back with the money for the bad check and also an apology. Over the next couple of years we became friends and we even had a couple of beers together at the local pub.
A lot of the guys and gals were afraid to get in arguments, because they actually relied on the income to support their families, and were afraid of getting fired. I was just working my way through college and could care less about the job, since I still lived at home. We were the only store in a brand new neighborhood, so we had a lot of repeat business. The neighborhood relied on us, especially in the winter, so it was important to keep the family atmosphere in our store. We had video games in the store too, so it was the local teen hangout, and we just couldn't have people cursing out the employees in front of kids.