HOw do I stop an unwanted fax from coming through?

Just looked up the Panasonic website.
www.panasonic.co.uk they may come up with a solution. I assume there is no ID on any sheet including the cover sheet as you've posed your question here. Next move contact your telephone/fax line server tell them what the problem is and ask if the phone/fax line can be monitored to obtain a sender number. They cannot give you that number re-privacy of information/security. But they can contact the sender who may not be aware their fax is going to the wrong number and ask them to remove your fax number from their system. Also you could ask the server to send the company a fax from you to the effect of re-imbursment of toner and paper losses. its worth a try.
Good luck [Ex BT engineer external construction]

Bob
October 2010