Hello. ----@charter.net is not a Microsoft account. Microsoft has nothing to do with charter.net. Microsoft is not affliated with charter.net . I think the internt company might be charter.net I would try to contact your internet provider. A lawyer is always best to take over any account. You can call the billing company and make a payment with out being an authorised user. You will need a lot of death certificates. I did the same thing when my dad passed away. You will want a lawyer to see if there was a will or what not. Also will need to hand the certifcates to the credit card companies , banks and so on.
-- Sorry for your loss.