I asked TiVo about who to talk or write to at Prime; they just directed me to this page which only gives a phone number - 0800 759 759.
However, these people then gave me the Prime TV office phone number, which is 09 414 0700, and their postal address, which is
Prime TV
PO Box 302193
North Harbour Postal Centre
Auckland
So, I tried calling them directly. They said I should talk to someone at head office... eventually I managed to get through to a nice lady called Jill who took my number and promised to call back within 24 hours with some more details as to what the stumbling block is, and to whom we should address our petition. She's not the right one to post petitions to or phone directly, though, so I won't give her full name so that she doesn't get deluged with stuff.

From what I hear it would be very helpful if as many people as can register this question either on the Prime website, or via phone to one of the numbers above, as they have had "Several queries already...". If you send a letter to the above address, it should probably be addressed to "Director of Communications".

Once I get more info I'll post it. If I don't hear back then I'll let you know...