WTF!! Are you SERIOUS!? This guy is an idiot.
...but at this point, he should be buying you an engine.
I would have to agree, the guy listened to him because "he's got a shop" and supposedly knows what he's doing.
This guys bad information IS the sole cause you need an engine right now.
Had you towed the car to an experienced mechanic you would be out 150ish towing and 100ish dollars to pull the plugs and get the water out.
250.00 tops....including towing.
now.. you need an engine and install.