Invalid decoder number for free installation

I app**** for a Price lock plan. My decoder was delivered a day after I app**** and the installer came to install the following day. Upon his arrival, he checked the box of the decoder and said the decoder number says its not valid for free installation and he left without installation. Before that he made sure that he made it clear to me that i was inconveniencing him, i dont know how because im not the one that delivered the incorrect decoder, that’s something he should take up with multichoice. I called the call center and was advised that i had called the wrong number and was given this number *** to call for pricelock queries. I have called that number on three occasions now and i hold on for an hour only for the line to hang up. I sent an email but no response. May someone please tell me what im supposed to do with an invalid decoder and no assistance from multichoice?