Jim, my first ? is, did they charge you for the repairs?
I just can't imagine any level wind reel wearing out the level wind worm gear unless you are using your reel to tow trucks! And even then, there would be other gears that would blow out long before that worm gear. I'm not familiar with the Shimano but looked up a schematic online and their worm gear assembly appears to be very similar to the Abu Garcia's that I have always used.
Sure seems to me that your Shimano must have had a defective part or possible damage not incured during fishing.
Just my opinion but if you had to pay Ollie's for repairs, you were taken.....
William