edit: decided to go through the process again, which it let me do, and this time it seems to have gone through. No idea what happened the first time. But this second time it took me through a final screen of options/agreements that didn't appear the first time I tried it.
I received the email about the price increase, and that I could renew my contract for 18 months and avoid paying the extra.
I went through the website link and extended my contract (as far as I know) but haven't received any kind of confirmation email at all. I have no idea to check whether it went through properly? Anybody help? Cheers