Central Bank Of India — Refund not received which was initiated on 15 dec 2020

Dear sir
I had purchased unacademy subscription from unacademy app and after ichoosing wrong course i applied for refund. I had purchased it with a central bank of India debit card on unacademy. Unacademy team saysto me that they initiated a refund amount of rs 19152/- with ARN 74163260351028382835621 on 15th dec 2020.unacademy team says that they completly successfully intiated refund amount on my cbi bank account.Now they says that the bank should have credited the refund on my account 5-7 working days.
But today is 3 jan 2021 and i havenot received any refund till now. Please refund my amount 19152/- at earlist.l complained against it on my bank branch but i didnot get proper solution from bank mannager and even they didnot know about change dispute foam and asked me i hear about this first time on your mouth.

Date 2 jan 2021
Dispute amount 19152/-
ARN/ reference no 74163260351028382835621