You're not the only one. See https://community.plus.net/t5/My-Account-Billing/Is-the-main-site-down/td-p/1767045. I'm typing this one-handed while waiting for billing to answer the phone so I can pay the bill they won't let me pay online. They blocked me just a few hours after telling me there was a problem and after telling me nothing would happen for a fortnight. I have now paid on the phone but why can't they at least give you access to the PN site so you can sort the problem out without having to bother Customer Service?