He went as far as txting me. He asked if he could call back.

This perv just did the same thing to my son.. He claimed he missed dialed but he did the same thing txt him for 4hrs asking him to "please call him back" my husband told him he was calling the NJ cops and he got scared and hung up.. THIS PERV IS FROM JERSEY

Contact your son's cell provider.  Ask them if the number can be blocked.

This number called me at 2am.....at least 5 times and sent me 3 text messages telling me to call. I talk in my sleep and I actually woke up and I was talking to somebody on the phone but I have no idea what they were saying. I hung up when I realized that I had answered the phone in my sleep. I live in Arkansas and I have a Chicago number. I text the number later and asked who the person was but no response. Creepy!!!