PUT me on your DNC List RewardsCo

I have made use of Rewardsco calling on behalf of Vodacom before and enjoyed the service. Recently I have been inundated by calls from ReWards co and after my daughter told me how rude they were to her I answered and asked for all my numbers to be put on the DO NOT CONTACT list. Agent was polite and agreed to do so but hey presto just had a call from them. Now I am demanding that I be put on this list.