What do you do if you have put petrol in diesel car?

STOP DRIVING DUMP THE ENTIRE CONTENTS OF THE FUEL TANK REFIL WITH DIESEL PURGE THE FUEL LINES REPLACE THE FUEL FILTER

PRAY IT'S OK

If you've done this and still have problems, the petrol has attacked various seals in probbaly the injector pump and or injectors. Could now get expensive. (Note that in cold countries, a 10% petrol addition is allowed to prevent waxing, so you may have got away with it?)