azure.com onedrive.live.com admin.microsoft.com microsoftonline.com office.com office365.com onedrive.com onmicrosoft.com sharepoint.com windowsazure.com
Each one of those portals take you to SOME view of your account with a gazillion settings. Many of them are repeated, and changing it on one portal doesn't necessarily reflect in others. For example, I enabled 2FA somewhere (and it worked), but going to admin.microsoft.com showed 2FA disabled.
Even payments, which every other website seems to have figured out, is broken. There was a recent change in regulations in India for subscriptions on credit cards that allow the customer to control the period of subscription, enabling/disabling, etc. Microsoft of course, hasn't implemented the changes (despite the regulations being notified in August 2019), and because of that, transactions are being declined.
So can I go and make that payment online? Well, no. Your subscription shows up as "expired" because it couldn't charge your account, and the only option it gives is for you to "reactivate" the account. Great, so I'll just reactivate. But no, it doesn't allow you to pay when you reactivate - it's going to try and charge your credit card again, itself, as a subscription, sometime. And of course, that's going to fail again. Loop!
Addendum:
So somehow, with the help of Microsoft support, I manage to sign-up for another subscription with the same licenses for the same cost, and they disable the old one. Great. So this time, it tries to charge my card, fails, but then allows me to "settle" the "overdue" amount manually. I do that, and my account is "active" again!
Do they send me a mail saying they've received the amount? Nope. Does my Microsoft account billing page show that I've made any payment to Microsoft? Nope. The only indication that I've made a payment is that my account is active with an expiration date in the future.