That's odd, but unless it was timed I don't see why you couldn't just leave it as it was.

There ought to be a phone number or helpline or an email address for help. Try that. Even if they don’t get right back to you, you will have made an effort to get the problem addressed… If it happened to me, the first thing I would do is clear my internet browser history and cookies and then try logging back on. Or if you you don’t know how to do that, turn the power on your computer or tablet all the way off (not just put it to sleep). Then try again. Often websites actually keep track of who is using their website by putting that data on your own computer instead of storing the data themselves… Be advised that if you made an error in signing into your account because you made a mistake in the password or user name they will often lock you out after 3 unsuccessful logins and force you to wait 24 hours or contact their support. Do you by chance have a sibling who might have tried to log into your homework account while you were doing chores? That might be the explanation.