Explora not working

Aug 2015 onair contact me for installation of the new DSTV explora and recommended that I use 1 of their installers Mamello Trading 903. Since the installation the explora is not working properly.I have phone onair aswell as Mamello trading so many times without any sucses. Since 6 December my secondary unit does not work at all!!!! Mamello trading keep telling that they will come and have a look while onair keeps telling me that they will speek to mamello trading. my last call to onair the lady said that I did not use 1 of their recommended installers, not true even today you can find mamello tradings details on the website of onair tv. So I have been paying for my DSTV that is not working. Such bad service I have never came across. What should I do???