Yesterday afternoon (about 5 or 6 hours after the initial discovery of the issue) it has rectified itself. The data has re-appeared and we are no longer getting an error in our app. We didn't do anything to resolve it.
My company and I are very unsettled by the unreliability of the CDS (this is the second outage we've experianced in 30 days) and I see no transparency for health or status like we have in Office365 and Azure (Please direct me where it is if I'm wrong). I'm also uncomfortable with it "Magicly" fixing itself. If someone at MS is seeing these posts and fixing it I'd like to see that as a reply i.e. "We fixed it".
I am now looking into running our own Sql Server on an Azure VM because I can't trust the CDS.