I am currently with O2 online and the retentions team could not really give me any good deals. Thanks to duckmagicuk2, I have found a couple of really good deals here. I prefer O2, as they let you use your inclusive minutes to call 0870/0844 numbers.
However, they say that if I sign up with O2 through someone else (to get 12 months free line rental, for instance), that I can not port my existing number to a new contract.
Is this true, and is there any way around it?