I'm fairly new to O2 and the O2 Community. Reading through new (6 Nov 13) and slightly older articles on the O2 Community pages, I get the impression that some people are not too keen on using Live Chat. I've contacted O2's Live Chat twice on minor matters and came away satisfied.
I feel a live chat in general is better insofar as there is less of dialect/accent problem than would be if talking via phone to a call centre in, say, India.
