What to do when a referral shop missed diagnose my car actual problem?

What is your question?

Previously work was performed on my car. Radiator water pump and from the invoice ghe teansmission oil line ,now the enging light is on! Took the vehicle to a small shop and was told the diagnose was a miss firing engine with strong coolant smell in the car

How long has your 2007 Pontiac Torrent had this problem?

Just yesterday