Airtel — Airtel forcing to switch Post Paid

Recently my uncle expired due to COVID and his mobile number is being used everywhere in my family and linked to Aadhar and other Banking Services, Since last 5 days the SIM stopped working says NO SERVICE, I have visited Airtel Cust Care with my Uncle Aadhar and Death Certificate Cust Support Executive said that they'll give me the SIM but they are forcing me to get the Postpaid Plan at least for 5 months which i couldn't afford and Even I have mentioned this infront of the Cust Support Executive that I Just use that number for OTP purpose then too they are forcing me to take POSTPAID.
Earlier also it was PrePaid SIM.