Bad service from multichoice

I have bought a DSTV decoder at game stores mams mall on 20/12/18 and was directed to go to multichoice for installation. I have since been waiting for installation for 7 days now and I have already paid my account, my next payment Is due on the 2nd, now I have to pay for something I'm not using.. The installation guys tells me about how he has other customers when I try to contact him. I have contacted him almost every day since I bought it with no success he doesn't show up at all.