Bharat Sanchar Nigam [BSNL] — Bill paid online but still bsnl says not received

Address:

jorhat, assam

Hello,
I have paid bsnl landline bill (of telephone no. [protected] for the month of july 2021) on 17 july 2021 by using online bill pay facility from bsnl portal.
money was deducted from my bank account but the portal showed error and did not update it as paid. the portal still shows the bill as unpaid and no confirmation sms has come through.
requesting you now to provide information as to how to go about correcting this.
regards
bandana gohain