Most junk faxes do not contain the number of the sender and many are not sent by the company advertising goods but by a separate firm commissioned to send out the faxes. Ofta says you can take several steps to stop the unwanted faxes.
Ring the advertiser and ask for your fax number to be removed from its distribution list;
To block all unsolicited advertising faxes, contact your telephone company and tell them to put your number on a do-not-call list. The numbers to ring are: PCCW 28887999, Wharf T&T 121121, New World Telecom 21331133, Hutchison 1220 and Hong Kong Broadband Network 128100.
If the faxes continue despite your requests, make a formal complaint to your telephone operator. If it is substantiated, the sender will receive a warning, which might count towards a suspension or disconnection of service under the new 'three strikes and you're out' Ofta rule.