Hello, I am so sorry you are going through this! They sound like my ex, I have been through the same. My ex used to call of a no caller id all the time, I found a setting in my phone to block all private numbers. check your phone make and settings, and you can also find help on the internet for that. if your phone doesn’t have it, you can contact your provider to change your number, which I did. You can do this free of charge aswell, aslong as you havent changed your phone number in the last year i think it is, thats with o2 though.
I am so proud of you for sticking up for yourself and standing your ground <3 I wish I did the same