Business account with 1KB of space not syncing

Hi there, I am an admin of a business account on the Standard Plan (5TB Storage), but I'm having troubles syncing any files across my organisation.

Although we have 5TB space available, it says on my account we only have 1KB storage (see screenshot). On my files, the error it gives me is 'Your Dropbox Business team has been downgraded and files have stopped syncing. See Next Steps' but clicking next steps brings me to a 500 error.

I don't believe there are payment issues as this is billed annually in April. Support haven't got back to me even though this is business-critical. Can anyone help?

Thanks, Alex