As someone who's been around awhile and dealt with various types of account and payment set ups, the changes that were (recently, I'm assuming since it's different than last month) made are horrible. Issues:
As I've mentioned, I've been a customer quite awhile and generally the service has been great (the random connection issues and excessive price aside), but this change is frustrating. I feel bad for the lady that had to deal with me on the support line, though I did apologize for coming off as rude. 😛
I think they removed e-billing a long time ago.
I use my Gmail e-mail to login. You just have to go to account management & add your personal e-mail address that you want to use. You can also reset your password from the same tab.
You should also be able to delete or remove a payment method under the pay bill tab as long as your role is set to owner.
I would visit https://mediacomcc.custhelp.com/app/answers/detail/a_id/9969/~/mediacom-id-management and there is sub tab of 'ID management' that helped me out.
I believe your comment is based on the old dashboard. It's been revamped and no longer functions the same. There is no "Account Management" tab anymore. The "Manage My Account" link under "Support" now takes you to the new dashboard. In any event, thanks for the tips!
Update: Ok, seems I did miss some "tabs", but only because they're just black text links with no indication that they're actually tabs. If the currently active tab had a background color or something, it might hint to what's going on.