mercedes slk 230 , 10 years old?

Change batteries in keys fob, disconnect batterie and re-tuned it. Fuel the car.Since the car start and died, tow it to the garage ..up the road . they cannot fix it, they try to change the ...(trushle) do not know what it is and the car refuse to accept the new part. I need my car to work and I am getting very worry , Maybe somebody could help

Beatrice
November 2010