Constant bothering with telemarketing

Elite mobile have been bothering me by calling me 3 times in 2 weeks. The first time, I listened and already have a Vodacom contract. The second time, I was rude, as I had told them to not contact me for the next 2 years. The third time I was furious. I feel sorry for the innocent call centre staff who receive leads of fed up telemarking. I told them to delete my number this time.