Personally I prefer email over phone, as then I can show them a trail of the discussion (and also have a reference number). It also saves re-explaining again and again somewhat as then I can just ask them to refer to the history...
I am following both routes. I have started a online query and that is even worse as I have asked this question 3 times now and they don't even read the question. They seem to have a cut and paste method going where they copy the answer they think is closest to it and paste it which is no where near what I am asking.
I am gonna flight this one to the end. Nothing fires me up more then when companies do this.