Ok so I have an idea that I am interested in pitching in labs I will get right to the point.
(Example) ::John buys £18.00 (9gb) goodybag but only uses 5gb GiffGaff will buy it off him for 400 reward points=£4.00 / this offer can apply to all goodybags excluding (always on data)
Summary :: 1gb = 100 = £1.00 payback for any unused data.
As the reward points system is in place this should be very easy for giffgaff to implement.
If you agree n like this idea could you please like the topic so I have an understanding of the ideas popularity in the cummunity. Thanks for all your support.