I'm having the same problem with my ex-boyfriend. I know it's a pain in the butt but what you need to do is just try to ignore it. When you get a text from him don't even open it just delete it. When he calls ignore it. It's what's best and he will soon get the message that you are no longer interested in him. I hope you the best and just remember to ignore him no matter what.
Rosanna-Symone