Airtel Payment Bank — irctc refund not received

Address:	Thane, Maharashtra, 421302
Website:	Airtel payment bank

Dear sir,
I have biiked tickets on irctc connect app, date of ticket purchased 04/03/18 mode of payment was airtel payment bank.
Tickets were cancelled on 13/04/18 & refund was rs 3680.
On 15th april, i have received mail that money was refunded to me with following details.
Date of cancellation of e-tickets-13/04/18
Refund processed date-14/04/18
Refund amount-3680/-
Refund reference no-zp56692e047f899
Payment gateway used - zaakpay pg.
For net banking it takes 3-4 working days & for card it takes 3-4 working days.
Previous to this cancellation, i have got refund in 3-4 days, only meaning i am getting that for large amount time for refund is more, it clearly shows company is holding my money to earn interest.
Kindly resolve the issue as early as