Citrus Cube : flat cashback of Rs.50 is valid on transaction values of Rs.50
http://www.citruspay.com/citrus_offers.html

Terms & conditions:-
The flat cashback of Rs.50 is valid on transaction values of Rs.50 or more.
The cashback gets processed automatically after your 1st bill payment: No coupon code is required.
The amount will be credited to your Citrus Cash account within 3 working days of your bill payment.
Grab your cashback amount by signing in to your Citrus Cash iPhone/Android app at http://bit.ly/1PS8V31.
Your Citrus Cash can be utilized towards all/any purchases at 600+ merchants.
The offer is only valid for a bill payment made until the 30th June 2015. So hurry!
The amount credited into your Citrus Cash account is subject to the Citrus Cash terms and conditions.
Citrus will withdraw the amount credited to your Citrus Cash account if you cancel the bill payment transaction.
Citrus reserves the right to not extend the offer to certain users if it believes they have malicious intent.
This is a limited time offer, and Citrus reserves the right to withdraw the offer at its own discretion.