Recover Hacked TikTok Account

My TikTok account was recently hacked and, frustratingly, the attacker also changed the linked email and phone number, so I no longer have any way to reset the login myself. I reached out to TikTok support, but their final reply was that they can’t help any further... (Budget: $250 - $750 USD, Jobs: Account Management, Computer Security, Customer Support, Internet Security, PHP, Social Media Management, Technical Support, Web Security)