1992 Buick Century crankshaft pulley

Engine Mechanical problem
1992 Buick Century 6 cyl Front Wheel Drive Automatic 196k miles

I RECENTLY HAD THE C/P R&R AND FOUR {4} DAY"S
LATER I WAS DRIVING ALONG, AN ALL OF A SUDDEN
A "CLUNK" AN THE CAR "QUIT". TRIED TO TURN IT
OVER BUT NO SOAP. TOOK THE CAR BACK TO THE
REPAIR SHOP THAT DID THE WORK. WHILE I WAS IN
THE "WAITING ROOM"I OVERHEARD THE MECHANIC
SAY THAT THE C/P WHEEL IS WOBBLING. SO HERE"S
MY. IF THE WHEEL WAS NOT PUT ON RIGHT THE
Ist TIME, WHAT DAMAGE COULD RESULT FROM THIS?AND HOW CAN I PROVE THAT THEY DID THE "DIRTY" DEEED. THANKING YOU IN ADVANCE.