When i was younger i'm working in a gas station has a pump assistant, and i accidentally put a full tank of diesel in a car using petrol !!! The gas station manager call a towing truck and send it to a nearby garage. The mechanic of these garage has explain to me by the phone that he will just have to empty the gas tank, and the vehicule will be ok. But he also explain me that is very more complicate operation in the case of you put some petrol in a diesel vehicule because you moreover have to purge the all system !!!
So my poor guy .... i think you dont have a choice of call a towing truck and going to the nearest garage !!!
And please !!! Do not try to start your engine with this unleaded fuel in the tank !!! Good luck my friend !!!