This isn't just any website. This will change the way you choose your phone contract: www.buymobilephones.net
Recommended by a colleague at work (who deals with money and budgets -trust him). This is a third-party website which allows you to either upgrade your old contract/stay with same contract but pick a free gift or pay less for the contract/minutes you have.
My partner last year decided he didn't need a better contract, so kept paying the same rate but chose a brand new laptop as a bonus gift.
I decided I wanted to lower my costs instead, so through this website I found a contract that offered the same amount of minutes/texts/emails/internet use for £20 a month rather than £35.
Funnily enough, after I told my phone company that I was switching through this website, they tried to offer me a counter deal. Firstly, it still wasn't as good as £20 a month and it was interesting that I had been with them for 7 years and they had never offered me any sort of deal. It just shows these companies can do better deals but they don't make you aware.