Sorry to hear that.
As I understand it purpose of the Primary Account Number(PAN) and the card is to provide identification for financial transactions and track them for tax fraud detection purposes. It’s not necessarily a universally accepted form of identification with a photo and signature, and this in view might fail the test for acceptable secondary IDs by being not acceptable as a primary ID. Perhaps ISC2 can consider reviewing it? One challenge I do see is anyone with an income in India can apply, and as its purpose seemingly is “Government gets money!Kerechinng!TM” I’m not sure how much effort goes into proving that the applicant is the applicant(signature on primary ID can support Signature on Secondary ID, and the issuing bank checks who they give credit/debit cards to.
You can find the acceptable forms of Identification here:
https://www.isc2.org/exams/exam-day#Anyway good luck and maybe try member support to see if they can help.