Get the fax call all the time from the SAME NUMBER...sooo annoying, lets make it stop

That noise drives me insane.
This number has called on two different phone numbers of mine.

We got my parents a new cell phone so they can be in the same network. The first evening after receiving the phone, the calls began (just one at first) and continue on. It will be only one ring, and then goes to voicemail where they have messages with "the beep." I instructed them to put the phone on silence. They even say the ring from a normal incoming call sounds different than the ring from this call.

What should we do aside from being assigned a new number? I am thinking that may be the fastest solution.

I just got a call from this number, and I could hear people talking. It left me a voice mail

I just started getting these calls today but have already had 6 of them in the last 4 hours. make that 7