Refund process varies with the mode of payment used while placing the order. For e.g. if the order was placed via internet banking, then the amount would be refunded to your bank account directly.
As for the duration, refunds for payment made through CoD/DD/cheques take 15-20 working days.
For credit card / debit card payments, refund processing time is 6-8 working days.
For orders placed through gift certificates, refund mode would be through gift certificate and a new gift certificate would be issued.