State Bank Of India [SBI] — charge dispute"refund not received"

I onder a product from amazon.I paid cash on delivery to amazon.For some reason i ask amazon for refund.Amazon inisiate my refund at 29/07/2019.But not receive in my accound.Amazon provide me refund refrence number of transaction is[protected].Amazon ask me to contact bank. I contact bank customer care of sbi but no solution. I contact branch but no solution.My account number is [protected]and account holder name is ankit kumar patel.where is my money i do not know or amazon do not know as well as bank not know.what i do?please locate my money.