Rude customer service agent

Good day I received a call from +*** on 13 December 2021 at 16:51pm. I was unfortunately not able to talk, due to me being called just a few minutes prior to go away on work for 3 weeks. I explained to the consultant that I am sorry, and cannot talk, and he should maybe try in a few weeks when I'm back, and proceeded to end the call. He then called back, and reprimanded me, saying do I think that he works for me, and I again explained I do not have time for this. I did end the call again, he then persisted calling and also from the number +***. I do understand that they are just doing there jobs, but I as a client am under no obligation to take your calls, whether I am busy or not, and for him to call back and reprimand me is totally uncalled for, unless he is paying my dstv bill, then he can have an opinion, I as a paying customer did not expect that kind of service or tone. I don't owe him anything.