Jiomart — No refund till date 20+ days

Jiomart customer care initiated refund for my declined transaction on 11-09-21.
Received mail quoting as follow.
"Dear Mr. Kumar,
Namaste!

Please note that a refund of Rs. 1259.80 has already been processed on[protected]. The ARN number for the same is WFRW[protected].

You can also check the same from your source account quoting the above ARN number."
Who knows arn number means.
Please solve my issue.