Logon to "My Account" fails

Logon to Comcast.net is successful, but when I try to access my credit card info or to pay my bill, I am unable to access that information.  Clicking the "My Account" button at the top of my account page only sends me to a grey screen, asking for my password again, and it ends up being an endless circle of logging on, entering my password and going now where.  Resetting my password doesn't work either.  I've chatted with and talked to Comcast agents (up to and thru a class 2 agent), tried three different browsers, I.E. Explorer, Google Chrome and Firefox with no success.  This has been going on since Oct 30 and one agent has told me that my problem is not an isolated case, that they're having this kind or problem elsewhere.  The best advice they can give me is to just keep trying to get into my account, that they're working on the problem.  And so it goes....