What happens when you try to convert PDF files to Word? Are you unable to log in, or do you receive an error when you try to convert (and if so, what is that error)?
I'm eager to help, but need a little more information to go on.
I checked your account, and see that you do have an active ExportPDF subscription. Are you, by chance, trying to convert from within Reader? If so, please make sure that you have the most current version of Reader installed by choosing Help > Check for Updates. You should be using version 11.0.07, as earlier version could prevent you from logging in to the Acrobat online services.