There were some recent changes to how payee accounts work which appear to sometimes be buggy. Try refreshing the page several times until the information comes up. If you're still unable to make the desired changes contact support so they can get you squared away. Hopefully this does get sorted out soon.
Clear cookies and caches of your browser. Change internet connection i.e. use another company's internet service. Some internet companies monitors the web traffic and they ban some scripts from web pages. I hope your problem will be resolved.
You can use a live chat option as an alternative to calling in for help. Chat can be accessed by clicking on the "Product Support" link at the bottom of our United States homepage. The hours of operation for chat are Monday through Friday from 5AM to 6PM (Arizona, USA time zone). Chat is available at the time of this message.