Treated unfairly? The property should have allowed you to check-in dispite the outbreak of Covid?

As far as I see it the hotel did the only sensible thing to do, i.e. explain upfront about the Covid outbreak and ask you to find alternative accommodation. You can't blame the hotel for not re-accommodating you; really not their fault that a guest got infected.

Unfortunate/unlucky yes, but you are barking up the wrong tree here.