2008 Volkswagen Jetta Starting Problems

Hello, for the past week my car has been having issues. The check engine light and the EPC light came on and the car started stopping and turning off in the middle of me driving. It also started to take longer to turn on and the speedometer was moving up and down. I had someone com and take a look at it and they replaced the crank position sensor and checked different issues such as the battery, removed the cover for the engine to check the sparks, ect. Now after they put back everything the car will crank but will not start at all. There was supposedly no spark when we tried to start it again. Can you please give me some possible explanations to what's wrong with my car?