As I've said, I've already contacted them, and gone through the rigmarole of sending photo's, serial number etc. The outcome was basically "tough, it's out of warranty".
I really can't be bothered any more. I've bodged it with a bolt now and, as far as I'm concerned, that's the end of it.
While I'm glad for anybody who's had replacements and is now happy, me being in exactly the same situation and getting the brush-off does nothing to make me feel any better about the brand. The whole experience simply means that my money will be spent elsewhere in future.