Indian Railway Catering & Tourism Corporation [IRCTC] — tdr amount not refunded

Hi i have filed a tdr on 29/07/2018 14:05. When i check the status it is saying refund approved and the payment is under process but i have not received my refund
Registration no= [protected]
Pnr no.= [protected]
Journey date=29/07/2018
Refund approved date=28/08/2018
Refund amount (Rs.) 425
Payment by traffic accounts office
Mode of payment apo
Pay order series 0031
Pay order no. 0031548
Pay order date 30/aug/2018

But i have not received my money