EZ Pay changes

I keep getting "technical" problem messages when I try to edit the credit card information on my account - this has been going on for several days. "An unexpected system error occurred. Please try again later." or "We're sorry, but our system is currently unavailable. For more information, contact customer support." - Customer support transferred me to technical support and another interminable wait time, but they suggested I return to customer support because I should be able to make this change online and the system is not down - so helpful!!!  I've restarted, cleared cache - all the usual advice.  STILL can't update the payment information. 

I've tried Internet Explorer and my usual Firefox browsers.  I can't find a block that could be affecting it.  WHO do I contact or HOW can I do it.  I'd hate to be delinquent on an autopay account but it won't be because I didn't try to update it.