Tracker / liquid telecommunication wont remove my number from their system

I would like complain about this company. They keep phoning my number 3 times or more a week looking for another person and everytime I tell them the person is not using the number anymore and to remove this number as it is a company number. They refuse to remove my number from their system and keep on phoning me. This is the worst service ever and the people there don't do their work. I'm not even one of their clients and they keep harasing me. I would like to know what I can do.