Received multiple hang-up calls over the last three weeks. Called back and either receive 'mailbox full' or nobody answers.

In one instance, there was a male voice on the other end who stated "he and his wife share this (cell) phone and he was checking up on her calls". I told him she obviously has a wrong number and keeps calling, and he stated that he will speak with her.

The calls continued after that, so I guess they are either play pranks or she's using my number to try and make him jealous. Either way, it's harassment. Suggestions?