You can stop that caller from calling in by putting their ph# in a table in the switch. Incoming calls are bounced off this table and if it matches it will disconnect the caller. -- KG - Utility company

We have also experienced prank and abusive calls. I can offer two suggestions on this subject. First, if it appears that the calls are coming from a young person, try to get in touch with the parents (this one could be more difficult since the calls came from different numbers).
Advise them that if the calls continue that you will have to initiate legal proceedings. Second, we have found great success by contacting the law enforcement in the area where the calls are coming from. Most police departments will make a courtesy stop at a location which has been very effective at stopping the repeat calls. -- Martin L. Mears, Ameren