I bought Minecraft but now it only lets me play demo...

What I expected to happen was...:
I could play both MC's one day, then the next I couldn't.

What happened was...:
I played a server with a friend the day before the bug happened, I turn on my computer the next day and load up MC (Minecraft) and it says I can only play the demo version, also says I no longer have the windows version of MC which I bought on my Microsoft account too. 

Steps to Reproduce:
There were no exact steps, it was just one moment I could play Java then the next I couldn't.