Constant Harassment

I am sick and tired of the constant harassment from the unlimited staff, every time they phone me, I say no thanks, please take me off your data base I did not give you permission to contact me, yes sure they say, a couple of hours go by and I get a call from another person. I have had enough of them constantly calling. Surely they are not allowed to call if we haven't given them permission; surely they are in breach of the POPI act????????