I have been with Giff Gaff using an Iphone4s since last October and get unlimited data. Never have they had to contact me about my data usage.
If you play by the rules, then you shouldn't have any issues with the service
Anyway, I would say £13 per month to include 250 mins, Unlimited texts and data and blackberry service represents excellent value for money.
We're setting you up on our systems, and you'll be able to use BlackBerry services within 24 hours (but it can be sooner). When your BlackBerry shows GPRS, EDGE or 3G, this means you're good to go.
If for some reason your BlackBerry doesn't display GPRS, EDGE or 3G, which is needed to use Email, BBM and internet, go to either;
Options, then Advanced Options, then Host Routing Table, then press the Menu key and press Register Now.
or
Options, then Device, then Advanced System Settings, then Host Routing Table, then press the Menu key and press Register Now.
If this does not work for you or if you have GSM appearing on the phone, take the battery out of your BlackBerry (whilst it is still turned on), and then put the battery back in and turn the BlackBerry on.
Once you have the internet working it is important to register your email address (email set up) to the device to enable you to agree to the Terms and Conditions set out by RIM Blackberry and to allow you to use Blackberry Messenger and also Blackberry App World.
These steps should get you up and running. If not, visit the BlackBerry pages on our website at o2.co.uk/blackberry. You can also find hints, tips and guides from our Gurus on YouTube, and if you need any further help or support, visit the help section on our website at o2.co.uk/help.
Make sure you don't top up late otherwise your BlackBerry services, BBM, Email and internet will stop working, and once you have topped up it will take up to 24hrs for your services to be working again. We'll always remind you before your anniversary date, so make sure you don't miss out!