Radio issues

Long story, but the short of it is that a company installing radios for McCarthy Mastercars in Gezina, cannot get the radio issue sorted out. I bought a VW bus and requested the factory radio to be replaced with a SATNAV unit and reverse camera. The first radio didn't work properly. They ordered a new one - no better. They then replaced it with a different make, didn't work. They then installed a \top of the range"VW radio"