Reopened my business but the google listing says permanently closed

Fix it everywhere else too. Google looks at your website, Apple Maps, Bing, Yelp, Facebook etc, and if one of those still says closed it muddies things. Put the opening hours on your homepage as well. Once it shows as open, adding a few new photos and an update to the profile doesn't hurt, it shows the place is active again.

Open your Business Profile while logged in as the owner, go to edit profile, and under the open/closed status there's an option to mark it as open again. Fill in current hours while you're there. It can take a few days to show publicly. If it keeps flipping back to closed, check the profile for suggested edits from Google, sometimes an old "closed" report from a user keeps getting re-applied.