“we don’t like your kind”. Works for me. I fired clients that weren’t good enough to be clients. One woman was a client for 27 years and got stupid…..byee, trouble.
I remember an early Dr. Savage show where Savage talked about going to a restaurant where a couple of kids were continually running around, fussing, etc. Pointed looks and head shakes didn’t phase the parents. The other diners took up a collection and dropped the money on the parents’ table and told them to hire a babysitter the next time.
When we took our kids to “nicer” restaurants, they were well-behaved. Our second was a fussy baby. If we were eating at a McDonald’s or Denny’s and he started fussing, I’d leave. Other patrons have the right to enjoy their meal in peace.