To answer myself, I tried calling yesterday and ended up at a message telling me to email
[email protected] - looks like you can't speak to anyone any more. I've emailed but I'm fully expecting the same generic "it's being processed" message.
My bet is they've shipped all the printed-out emails and forms from MoF over to MTO in a vast amount of boxes and they're waiting for some skeleton crew to start working on them when they eventually get moving after the holiday break.
I think I'll do an ombudsman complaint too - it's been over six months now, not unreasonable to at least be able to get status if not the payment.