HOMECHOICE spam calling

Homechoice call me 3 times a day for past 2 or 3 weeks, and no matter what number I block they keep on calling from another number. My domestic worker bought a cell phone from them and gave my number up as her "work number" and now they keep on calling, looking for me! Every time they promise to remove my number from their list but I still get calls every day! They are trying to sell more marketing products using MY NUMBER. How can I be removed from all their databases and lists? I get calls from Cape Town (021) and Durban (031)