We are experiencing the same exact problem today. We simply want to renew our domain, but cannot figure out how to do so.
On January 14th, our 'Domains" page (from the "Store" section of our "Dashboard") stated our domain would expire in 13 days. Thankfully, I captured a snippet or image of what our dashboard displayed that day. Yet, today, January 23rd (just 9 days later), it says our domain is "expiring".
Anyway, just thought I'd let you know we've got the same issue. So, if you figure out to renew your domain, could you let me know via email at [email redacted]? I'd be happy to do the same for you.
Best of luck!