My question involves education law in the State of: Virginia.

I am an out of state graduate student and typically pay out of state tuition. At the beginning of the semester I was classified as in state, which I assumed was because all classes have moved online during COVID. The university used my loans to pay the tuition, and then disbursed the rest to me for my living expenses. Today I received an email of an outstanding balance of $8,000 on my student account. I checked and it showed that they added out of state tuition to my bill. I have no idea when or why this was added as I never received any emails or notifications of it. The university never sent any emails or made announcements about tuition changes either before the semester or during it. Am I responsible to pay this added amount? If they made a mistake in giving me in state tuition and are now demanding the out of state addition, am I required to pay it even though I was not informed and already paid the tuition amount they initially asked for? Is it legal for colleges to charge extra tuition costs midway through a semester?

I am really stressing out, thanks for all your help.