DStv calls from a call centre?

After putting my problem to Hellopeter, DStv promised (for what it is worth) that they would attend to my problem of receiving zillions of calls per day from a call centre appointed by them (my deduction from the response when I answered these calls - "DStv appoints us to inform/ask/etc. you ...."). I am irritated by these calls (you cannot block the number, because they have hundreds of different numbers). I have requested that my number be removed from these databases, but it seems my request is being ignored. What more must I do to stop this harassment?