Well, last night, I broke my duck

So pulled into Leigh Delamare, stopped at the pump, stuck in the nozzle and filled the tank. Click, tank filled, put the pump back on the cradle and the rhe realisation hit me, I had just pumped 50 litres of unleaded into my diesel tank

Good thing was, I had not started the engine, so no petrol had been sucked into the engine or injectors.
So, on the phone to Green Flag who confirmed that my policy covered missfueling and they said that it was quite busy (It was 5.45 in the evening) but they would have someone to me as quickly as possible. Their policyis to be on scene within an hour, but the text I got from them suggested nearer 1 hour 30.
Anyway, long story short, within 20 minutes breakdown van on scene, very freindly and professional technician who had the tank drained and car running within 20 minutes or so and I was on my way. My cover also included 15 litres of diesel at no additional cost, although I did fill up properly just to make sure that any residual petrol was diluted.
So within 1 hour of missfueling and making the call, I was back on the road and the car never missed a beat.
So, to Green Flag I say thank you, very impressive, freindly, profesional and expedient service