I'm really sorry you too were experiencing issues with your mobile data. I'm also sorry we haven't got back to you sooner. Not sure why you slipped past us.
The system I use to check network outages only shows data from the past 7 days. So I can't say for definite if there was an area fault. I suspect there was though as I see no other reason as to why you'd lose your internet.
I'm pleased to hear it's now working again. Please let us know if there are any further issues and we'll get back to you as soon as we can.
Thanks @Rich-B but still intermittently having no data connection (despite showing 3G connection) - this is in the Hammersmith Road W14 area near Olympia - it's not the phone or settings because all works fine everywhere else in London and the UK! Is there a currently known problem in the area please?