Engine problems after Ford SA factory recall

In March 2021 I took my vehicle, a Ford ranger 3.0tdi 2009 model, to an Ermelo Ford dealership after several sms messages from Ford SA to do so. The vehicle started to cut power off whist driving, especially at a speed above 100kph, later 80kph and now can't exceed a speed of 40kph or above 300rpm. In my initial complaint to Ford SA,I was advised to take the vehicle back to the dealership for a diagnosis, which became worse. After several attempts to get the intervention of Ford SA, I was told that they advised me to take the vehicle back to the dealership so that they would correct the mistake, but following poor cooperation from the dealership, they couldn't continue with my matter. I'm now not able to drive the vehicle for a long distance and time as the engine just switches off. Can you please intervene, since my bakkie was in a perfect running condition before adhering to Ford SAs instructions as a way of complying with the manufacturer.