Purvanchal Bank — Money not credited in my account

Address:

Nakti dei bujurg, post kaptanganj, district basti(UP) , pincode 272131

Am Ajay kasaudhan account holder with this bank My account no. Is [protected]
IFSC code - SBIN0RRPUGB
There is a amount of 1699 have not been credited in my account from Amazon and the refund refrence number 30005412351231164018413.
I went to the bank with this RRN and they denight to help me out and please help me and return my amount as soon as possible.