key fob not working on focus c max?

my fob was working ok until guy came to change windscreen, he unlocked doors using fob then unlocked bonnet and left key in lock, after he had finished neither the heated element on the screen nor the key fob work! have tried the re setting programme ie turn to pos 2 x 4 in 6 secs etc but nothing happens, windscreen co say they have,nt done anything blah blah, anyone got any ideas please