MOBILE CONVERTED FROM POSTPAID TO PRE PAID,REFUND HAS NOT BEEN RECEIVED

MOBILE no.9423005173 was cancelled post paid to prepaid on 22/07/2017,covering list no 1629 dated 17/10/17
so far Not received any money against Deposit or no REFUND OF DEPOSIT.
WHEN IT CAN BE DONE ??
I ALSO WANT CLAIM FOR INTEREST ON DELAYED REFUND ?