Not getting what I want

In February 2015 I had requested two explorars for their specials at R799. I only received one. I have been complaining and requested that either they give me a second decoder or come and take their decoder because I was not going to pay for every time that my decoders are going to be installed. I ended up keeping quiet because Multichoice has kept quiet. I was surprised last month when I got a call that I am being charged a figure of R99 for the decoder, when I complained again I was told that my matter will be escalated and nothing done. I am now being charged an amount of R99 (which is incorrect it should be R799) and also I have not received a second decoder. Last week Thursday someone from multichoice phoned me and I told them my story and I was told that the second decoder will be delivered within 24 hours it's already a week later and nothing. All I want is that a second decoder be delivered so that I do not have to pay an installation fee twice.