I have the same problem. When I go to edit it, it shows me the cap, lets me choose a new cap, but when I hit Done, it just says the service is not available.
This used to work a year ago - no doubt one of the many website upgrades broke it. Most of the services on the website are now broken for me - cannot see full usage, cannot see addons, cannot change spend cap. All I can Replydo really is see the spend cap, see the phone numbers on the account, and see the last bill amount. Everything else appears to timeout and gives an error of one type or another, saying to try again. I have tried many times, over 5 days now - clearly the problem is not system load - its brokenness.
