I got this a while ago on EE (UK too). After running out of data, everything stopped working. Didn't realise data was out, assumed some network stack catastrophe so power cycled. Then after reboot all web traffic was being redirected to my account management page; I started a new weekly pack via text (more difficult/impossible via web), but then even after a wait and confirmation texts web traffic was still being redirected. Something somewhere was caching something or not re-registering. Ended up power cycling again too. Frustrating.