But we're also assuming that it's him calling and hanging up on the mobile. I get loads of those kinds of calls every day from debt agencies and things (when you sign up for a credit card online, ALWAYS check the "don't pass my information on to third parties" box - *sigh*). Unless we know it's him, it's hard to presume.

And so he still shops at the same grocery store that you used to together. Is that a crime? Maybe he likes the vegetables.

Most of this is circumstantial. As you've stated, he's not spoken to you, so I wouldn't consider him a threat.

I'd try talking to him and setting him straight, and if that doesn't work, then consider getting authorities involved