Ouch, that does sound like a complete clusterbuck on behalf of the RACV. I hope they resolve it to your satisfaction, even if it comes down to fuel in the tank! I'm glad I was of a little solace to you, and I did get a chuckle from your lawnmower man reference (one that would be lost on my kids).
It just seems crazy that a RACV "mechanic" can get something so simple, so wrong