Forums are totally pointless there's not a thing they can do for you if you just want advice about mobiles go on a proper site. Think it's about time you got a proper customer service department
This forum was able to tell you that your iPhone5 is the reason why you can't get 4G on giffgaff. (The iPhone5 doesn't support Band 20.)
How is a "proper customer service department" going to give you more help that that? Are they going to give you a free replacement phone? They aren't likely to tell you to go to a different network, which is the only real alternative to changing your phone if you must have 4G.
There are plenty of members on this forum who will happily give you advice about alternative networks that can be used with your phone.
We could even suggest that you use http://maps.ofcom.org.uk/check-coverage/ or http://kenstechtips.com/index.php/mobile-operators-explained-virtual-networks-and-coverage#Check_Com... to investigate coverage on the other networks before wasting time and money on joining a network that doesn't cover the locations that you need.
@rymorgan Sorry can't agree with you there. This forum offers help and very quickly if people are in need of it. Much quicker than searching google for the answers. Apart from the help forum it offers many other people a social platform as well. For many it is far from pointless
I've just looked at the giffgaff marketplace for pre-owned phones and I can see they have the iPhone 5S for £99 which means that a helper on this forum could earn enough payback on this forum to pay for the phone within a single month. (Payout is only once every 6 months, so it could be quite easy to earn that much in 6 months, if you take the trouble to learn how giffgaff works.)
So this forum could indeed solve your problem of not being able to get 4G on an iPhone 5...
Sorry to hear that all is not well for you ( re compatibility between your phone and the 4G band that giffgaff use ) , but blaming that on the forums isn't really fair ..... This IS a " proper site " , in fact as far as Help and Support is concerned it's more than likely the best there is , No call centre has the same level of expertise ( over a very wide spectrum of phones ) that is available from the knowledgeable and friendly members of this community ( who are always available and ready to help ) .