Hello and Welcome..
My name is ***** ***** Im happy to help / advise you ..
Im assuming the tank was fairly low for you to go for fuel... If thats the case - putting that amount of petrol in - then if you filled the tank right up with diesel -the car engine will likely not even "notice" it ...
The strict / pro answer , is that you should have the system drained immediately and put right... but in all honesty - as above... will be the case... but do let me know if you need to discuss it anymore at all..
*** Meanwhile - - >>>> Please do click on the "OK/ Excellent ratings" for me - Thank you in advance for that...You can and are most welcome to get back to me anytime you might need - clicking the OK ratings does not close you out at all..Kind Rgds, MIKE.