@Ashenafi0 Don't let this guest bully you. I would tell him you can't extend him, reverify the check-out date and time and get him to confirm he will leave on that date.
You can check VA laws on tenant rights, but I believe since it has been only 28 days he can't claim he's a tenant, so once the reservation ends he is at risk for being ousted by police for trespassing. The police tend to have unpredictable reactions to Airbnb issues, sometimes they think it is not a police issue, sometimes they do...but if push comes to shove you could certainly threaten to call police even if you did not intend to do it. Good luck.