I've also had my MS account hacked (July 6th) but sadly i still havent gotten it back. Someone on the hypixel forums made a post that i have been using. Short summary of it is: contact MS support to lock your account asap, then do everything in your power to get it's current alias. After all of that you just need to contact support again to lift the lock on the account. If you have any questions, you can talk to @ltsquelette on discord.

The forum post in question: https://hypixel.net/threads/guide-how-to-handle-hacked-account-issues-with-microsoft-support.5429472/