multiple calls from this number

this number sometimes calls me 3 or 4 times a day, i never answer it, they never leave a message...

I have been receiving 2-3 calls per day for the past few weeks.  I actually answered it but there is nothing on the line.

Multiple calls received.  No messages associtated.

I have received numerous cals from this number. I answer but there is never a person or message associated with this number. I lve in Ontario, Canada. I wish they would stop it is very annoying. Thanks