Unhappy customer

We bought a vehicle end March 2017 at Barons N1 City. Brand new Golf 7 with service plan and warranty. Everything was fine until the car came back from its 30 000km service middle last year. It's cuts out while we driving without any warning signs. It then says start engine manually. Then with the little power still left in the vehicle I pull to the side of the road. I switch off the car completely the restart. Sometimes it starts immediately and sometimes it struggles to start. I have recorded this on my phone. The first time it happened I took it too Barons Culemborg in Town. They told me Barons N1 City did not updated the software and they will do it. I got the car back and was driving fine for some time and then the problem started again after a month or so. This problem is intimitent so I don't know when it will happen again. I took the car to Barons N1 City where I bought it. They told me this problem does not happen with them so there is nothing they can do although I've sent video clips. Every time it happens then I take the car back to them. It is dangerous as anything can happen. We did not get any enjoyment from that car from middle last year up until now as driving a courtesy vehicle. They told me I must do a trade in. I am not happy with that as I must start all over financing a new vehicle and it is not my fault. I bought a new vehicle and not a second hand one. End of this month will be two years we have that car which we only enjoyed that car for about 1 year. I am unhappy although I've sent the video clip to them when this problem happened. I feel discouraged as they don't care about me as a customer it is just a SALE to them. I have asked them to email me job cards of all the time I took the car to them but still nothing. The only email from them is deal for a trade in and buy another car from them. They tell me about the dealer principles but I have my proof on video clip. For us it looks like an electronic fault. I will be glad if they can fix it but they're answer...It doesn't happen with them so there is nothing they can do. I still have their courtesy vehicle. Never skipped a payment although I paid for a Golf 7 but drove a Polo Vivo from mid last year up until now. What if this problem happens again and it struggles to start then someone can come to the car and hurt me. I have even asked them the question. They just mention a trade in. I don't want another vehicle from Barons as I am unhappy with the service I got from them in this regard. They will just sell that car to the next person and tell him the same story.