Okay so here's my idea let me know what you think..
So at the moment when you begin to run out if data you get a text which is similar to ''just a quick heads up you have used 80% of your data" now I don't know if its just me but when I get a message like this i immediately want to go and check my remaining amount by going to the giffgaff dashboard. This is all well and good but just to make things simpler why not include that info on the text? This is nothing revolutionary but would save people time having to go to the giffgaff website / app. It would look something like this:
"Just a quick heads up
you have 100MB of data remaining"
Also in some cases going into your browser to search giffgaff can eat up more data (including background data) so this would stop that from happening.