AirTime rewards you cashback towards your mobile phone bill.
Many retailers participating, including Argos,Halfords, 3-5% cashback usually, you need to register your card number you use in stores.
You can claim money off your phone bill in £10 and £20 when you reach it.
To get the £1.50 bonus use my code DMVPPG6F when you sign up.
Here is my progress so far: