VW refusal to repair my vehicle when it ws still under the motor plan

I bought a VW Tuareg in 2008 from a dealer in PTA. After a while the vehicle would loose almost all power when I wanted to pass another vehicle. It would not do it all the time but I never knew when it would happen . I reported the problem to the dealer who referred me to VW in Rtb. MY VEHICLE WAS STILL UNDER A MOTOR PLAN WITH VW . BUT It was never fixed After many enquirers and threats They had my vehicle in Rustenburg VW for almost 2 months for this repair. They eventually called me to inform me that my vehicle was fixed. I informed the workshop manager to drive it and we were nearly ****ed because nothing was fixed. Now the motor plan expired and I still had the problem with the vehicle. VW just laughed me off and said I was now responsible for the disorder . How can a fault that they never fixed under the motor plan now be my problem. For almost 13 years me and my wife's lives were at stake because VW would not take responsibility for a fault that was never fixed when my vehicle was still under the motor plan. I even spent over R60000 to solve their problem on my car. Please help me !!! Im 71 years old.