Punjab National Bank Housing Finance [Pnbhfl] — Denied service for swapping repayment mode

I am having house loan from PNBHF:
HOU/NOIB/1220/846953
HOU/JAN/0318/511496

During loan sanction I requested them to repayment from saving account. They assured me you can swap to saving account after 1 year.
Now it has been more than a year, they are denying my request to swap the repayment mode to saving account.

All the banks are providing this service, but they are rejecting this service.

Please help me.