Annoyance calls are a fact of life, every time a new number gets put in service someone somewhere will eventually find it.
The Voiceway system has a nifty little feature to help you cut these out, it is Number Blacklisting.
You can blacklist calls through your phone or the Administration panel
On your Phone you need to do this immediately after the undesired call is received (before another call comes in). Simply dial *32, and the system will tell you the number that just called, and instructions to confirm the blacklisting. Once confirmed, the system will again tell you the number, and that it has been blacklisted (doesn’t work if they have blocked caller ID, but there is a way around that too)