Pricelock does not to pay the installer

I took a package of DSTV Explora which comes in 2 decoders. they first delivered the first decoder after w eek which I got it installed. we called DSTV to ask if installation was indeed for free which was confirmed. 3 weeks later the second decoder was delivered and I called the installer who asked me to call multichoice and confirm if installation was for free, which was confirmed to be free. but now the installer is busy calling me telling that multichoice are rejecting his claim and they have told him to come demand for his payment from me. he even came to my house and this is annoying me. I have asked DSTV many times if installation was for free for both decoders and it was confirmed. can you please pay him or tell him to stop calling me because we will end having a physical fight. I will never pay because when I apply I was told it includes free installation and I asked many times, its recorded you can listen to the recordings.