Throttle problem

Throttle wiring problem. My car had this problem fixed at vw Acardia last year. And in less than 12 months it happened again. They made me pay R13280.00 even though they say they have a 12 month guarantee. Worst of it is I took the car for service the day before it broke down and I told them about it. They said they checked it and the was nothing wrong. Only for me to get stuck on the road on my way to work the very next day. I'm a doctor people die if I don't make it to work on things that could have been prevented.