Flipkart — Not yet received my refund

I have recently in the flipkart big billion days ordered my poco m2 pro on 18/10/2020.On the same day I cancelled the product .They told me to get a refund by 23/10/2020.But i have not been credited yet .They have given a reference no and telling to contact the bank service but the bank service is refusing and they are saying that if we get any such payment we automatically reflect it back .They are telling to contact the flipkart customer service.
I want my money back anyhow otherwise I'm gonna file an fir against flipkart.
My reference id is
onus20201019
Payment to be credited id
12999.