Telemarketing harassment from Lifestyle Management

Why does Telkom Mobile appoint Lifestyle Management ***) to continuously harass people using other mobile service providers? Hoe do they get our numbers in the first place? I've been contacted four times in the last week from this number. I phoned them and they said that they are the official marketing agent for Telkom Mobile. I checked the number online and many many people have complained about aggressive, rude and incessant calls. Please stop. This is harming Telkom's name.