Just to update , dunno how I managed as obviously the mondeo is diesel , my transit is diesel aand the wife's shogun is diesel but I managed to put £50 of petrol in (still think it might be the garages fault ) drained the tank last night took the injector pipes off and emptied out the common rail put a new filter on and put diesel in the tank and hey presto it runs fine now , when I discovered the error I reaserched it on line and was gutted , thought the engine , pump and injectors would be fooked but so far so good , I reckon I must of done some where in the region of 35 - 40 miles with the petrol in and was surprised it was running all be it badly !