STOP HARRASSING PEOPLE

I have been an MTN customer for more than 10 years. I have always been haply with their service and have no complaints there. BUT their marketing team is awful. I get harrassed DAILY. I have spoken to the people calling, and I kindly (the first 3 times) asked them to please stop phoning me everyday about promotions and forcing me to go onto a contract. After a while I started getting impatient and impolite, with the hopes that they will understand. Nothing works. THIS IS HARRASSMENT! If I ask you several times to stop phoning me every day, and you still do it, you are harrassing me. I AM ALREADY YOUR CLIENT, you don't have to win me over, you can stop.