Last year I phoned then and sorted it out then. The other option is to buy a single update from someone like gps.co.uk
Download using the skybound USB adapter. They were offering this free at Oshkosh recently if you were taking out/renewing a subscription. Might be worth a mention!
I had an email a month or so ago announcing the ability to pay or renew online but it sounds like it's not working from what you've said.
HTH
kui