This whole sham is pretty unforgivable on its own but in case one was feeling like giving Apple the benefit of the doubt, the final nail in the coffin is the level of support that's been provided i.e. none. I've sent three emails since the weekend and have received no response and, it seems, the live chat options that were available on the website for .mac have been removed.
Does anyone have any tips on how actually to get a response?
Don't email because it gets you nowhere. Just Call them.