State Bank Of India [SBI] — trace down my refund with arn

Address:

East Sikkim, Sikkim, 737101

My name is Tshering Uden Bhutia
Bearing account number [protected]
Recently on 27/8/2018 I got a refund of 300$ from 70trades in my debit card but the amount has not been credited into my account.. they have provided me with an ARN number 74046108158020902485887 but the bank is not being able to help me to trace down mu missing money .. do help me out