EPC light

I had a cam belt done in January and about a week later I had a eml light come on and when scanned showed as a cam shaft position sensor and engine speed sensor at fault but had never been on until the cam belt change. I took it back to skoda who fitted this and it was found to be out by a tooth on the crank they corrected this and ever since at least once a day it judders when I pull away but it went into safe mode yesterday and had no throttle response but could reverse it. When it was at idle the rev needle was moving between 1k and 1500 rpm is it possible the tooth out could of damaged a sensor?

Any help on this would be much appreciated.