I'm very happy with my new mobile phone provider smarty.co.uk
It's a piece of cake to sign up, transferring my number went like clockwork and now I'm only being charged for the data I use.
If you're into excellent customer service, an easy bananas UX on the website and fairness and honesty I can recommend these guys.
It's not just about the money.
It's about being treated with respect instead of billing me if I don't use all my data or immediately cranking up the bill if I go over the limit. That's just pick pocket mentality and there's too much of it in business.
If you use this link to sign up, you get a free month, and so do I.