Cannot access account.microsoft.com to pay past-due Microsoft 365 subscription

I can sign in to Microsoft Support, but account.microsoft.com/services is stuck in a sign-in loop.

I have tested this on multiple computers and browsers, including Edge and Chrome, and the same issue occurs.

I have a past-due Microsoft 365 subscription. My previous credit card was cancelled and I have already added a new valid credit card. However, I cannot access the Services & subscriptions billing page to pay the outstanding balance.

How can I clear the past-due balance or contact Microsoft Billing Support to process the payment using my new card?