Telkom hands out personal details without consent.

Telkom has sold my personal details to 2 foreign companies (that I know of): Infobel in Belgium and za.ypgo.net based in Lithuania. These companies advertise my business, using my personal telephone number, which causes a lot of disruption in my family's lives, as well as in mine. I did not give consent to Telkom to give/sell my personal number to anybody and I would like to know if this is legal. This is a major inconvenience.