I have had calls from this number for a month now and its driving me mad! there MUST be a way of stopping these calls.

Who are they? Someone has been trying to send me a fax since yesterday to my work mobile number and, as with all fax machines, it's set to auto redial consequently leaving me voicemails of a beeping faxing sound. I tried to send the number a fax yesterday and again this morning informing them to check the number they need to send to but the confirmation report is coming back as busy!! I've tried to call the number but get cut off after a couple of rings! It's driving me insane!!! How can someone not know they are dialling a mobile number?!! The first call I got today was this morning at 5am!!! I would really appreciate your help. Thanks in anticipation...