Issue with 2012 Trailblazer DVD /SATNAV system

GRID Electronics supply GM with the factory fitted DVD/SATNAV system for the first Trailblazers that came into the country. I bought a second hand Trailblazer with ll the warranties still in place. From since I have the car, this DVD/SATNAV system gave me problems. I reported it to GM who contacted GRID Electronics. My vehicle went in for the system to be taken and and sent to GRID in Jhb. When the system was installed back into the car it was even worse than before. GRID Electronics is trying every which way to get out of this situation. I am not the only one with the problem. I know of at least 3 TB with the very same problem. GRID, When are you going to owe p to this issue and satisfy the customer ? ?