Yeah, I realise it seems pretty funny from the outsider's perspective...
However, I'm 95% sure that it was my fault: it distinctly remember using the 98 octane unleaded nozzle (in green vs. black and orange for the diesel nozzles at this station - Total) and my receipt shows that I was charged for 98 octane. So, I'm thinking some moron filled the wrong pump with diesel...
Anyhoo, been having "fun" sucking diesel out of the tank (doesn't even give you the same buzz as petrol - but tastes less offensive

). Unbolting the tank and flipping it over didn't release a drop - I think it is designed to do that though. Couldn't figure out another way of draining the bastard - had a look at the fuel pump "flange" thingy: not convinced that it is worth the trouble of un-plugging.
Next task for the weekend is cleaning out the plugs and then the moment of truth!

Wish me luck folks!