Jackson Shatner

I have an up to date payment method (and can buy lindens) but the website won't let me upgrade my account in order to buy land. Interestingly, when I do try to buy land, it tells me "your account will downgrade to Basic Access on Thursday, January 1, 1970." I've been in SL for a long time, and am proud of that fact, but not even I have been around that long. Any ideas?