State Bank Of India [SBI] — refund not credited on my account

Address:

lala bazaar almora, Almora, Uttarakhand, 263601

I made a purchase from amazon.in on 11 august 2019 and because of some reason cancelled my order the very day. I had made my payment via atm card.

The refund was initiated by the merchant. The amount was supposed to reflect in my account by 20 august 2019. But today is 27 august and i have not yet received the refund. I called the bank's customer care but they failed to be of any help.
The refund reference code (Authorization code) is 784126
I want my refund of rs.538.00 to be made as soon as possible.