When I was a kid or even in college, I’d stop talking to someone if I was mad with them. That was just being passive-aggressive. I’ve grown up a bit and tell people when I’m mad at them. Just did that with a friend of mine who is a valued business partner, and things went OK when the business partner apologized.
Most of the time, it works. Sometimes it just doesn’t. I’ve had friends and plan providers write me off for good, just because they didn’t want to accept responsibility for their mistakes or bad conduct. You can only control yourselves, not others.
If they matter to you, tell them when you’re mad.
If you matter to them, they will accept it and move on.