This is something I created mid-July last year and have been expanding on ever since. It's one of the biggest things I've ever worked on as a moderator of HUKD but I'm never sure just how useful it is because it's hidden away in the Miscellaneous forum. It's also a sticky and it seems they are always totally ignored. ;-)
It's a post. A big post. And within this post you'll find all of the mobile phone help you could ever want, mainly for contracts. It's pretty much a list of links to other useful threads. These include individual threads where you can leave and read feedback for the mobile phone retailers for how reliable their cashback was, leave/read feedback for the service each of the UK networks provide, find advice on how to succeed when claiming your cashback, external links to websites and forums with information about unlocking, free downloads for your mobile, find out how to get cash for your old mobile and you'll also find spare cashback forms for e2save, The link, OneStopPhoneShop, CoolNewMobile and PhoneboxDirect. As well as feedback for each retailer, you can also find extra information such as how much QuidCo cashback they offer (although this can change regularly) and also, newly added, contact details for each company including email addresses, telephone numbers (and geographical alternatives) and where to send your cashback claims.
It really is an exhaustive resource. For the simple reason that if you think I can improve on it in ANY way, if you have anything to add or if any details on there need correcting then all you need to do is tell me and I'll work on it ASAP.
To access the thread, simply click on the "go to deal" button, click the link in my signature at the bottom of each of my forum posts or visit the Miscellaneous forum where it's pinned in the top few posts. I hope this helps.