I'm going to refuse any contact with my ex since we broke up
What's your reason for not wanting to be in contact with them?
I have nothing to say to them. I just want to ignore their phone calls and messages.
It's really okay if you don't want to have contact with your ex. Since you are no longer together you have no obligation to be in contact with them. Maybe you could ask them to stop calling you and sending you messages.
That's a good idea. I'm going to tell them to stop contacting me.
I'm glad you're setting boundaries with them. This will probably make both of you much happier in the long run.