Unable to come back(fallen ill) within time of AP

[PAMA]

I am us citizen who has filed for green card for his father.he came on tourist visa ,I 485/130 dates are 13 July,23.AP was filed on 23 Aug,fingerprint for 485 done on 12th September. Emergency AP given on 13th September ,valid till 13 Oct.My father went to India for urgent work on Emergency AP recently but he got ill now and was not able to come back by 13th Oct,I have doctor's detailed note explaining why and when he can fly next, is there a way to
A. Can i Send letter to 485 service centre and 131 service centre with doctors note explaining why he can't travel back by 13th Oct and ask for them not to cancel his process
B.if that won't work what's my next option

C.Normal AP us still pending,not sure what happens to it
Please help here as I want my father to be with me as soon as he is able to fly (attached are existing AP and doctor's note),if needed Doctors note can be more detailed or change of language etc is possible

EMERGENCY_AP.pdf Doctor_note_illness.pdf