Done the same and had to endure an hour in a yellow oven whilst the AA driver sat up in front with my wife. Let the record state that I filled the tank.
Could have been a lot worse - (diesel in a petrol car) cause that screws up the injectors, and the system needs a good steam clean, whereas once you have got the majority of the petrol out, you at least only needed to stick some diesel in and away you go.
don't listen to the garage who tell you it'll be £200 to take the tank out & clean it. they did that to swmbo when i wasn't around, bunch of cowboys (citroen main agent)
My Uncle Charlie put diesel into his Grenada just entering Spain about 30 years ago. We followed him for over 100 miles with black stuff belching out, stopping at every station to put in another 2 litres to dilute the diesel. As kids, we thought it was hilarious. It finally cleared on the way back out of Spain 2 weeks later. It ran like a bag of spanners, but he refused to waste the liquids paid for!!
<hr width=100% size=1>Second Chance - First Love. Look for the Yellow Dinghy in Burnham.