The 3 basics for an engine to run. The problem I find with todays tech's is that they forget the basics. The first thing they do is hook up the bike/car to a computer and cross their fingers that a direct fault pops up and tell's them what part to replace for a remedy. In this case I think his bike was dumped onto the youngest guy in the tech pool and he was too proud to say he was stumped. Just postulating here.
Hope you get it figured out. I don't know about suing (this ain't the U.S.A.), but you could have a case for small claims court depending on what it says on your bill.