Problem with getting back my account

Hello. I had one account in fashion niche with 80k followers. I have original email, so I can get back my account by changing password. I have to send a form to instagram that my account is stolen, and they send me link to change password. But here is my problem. Last time when I tried it I log into my account, changed email, phone number, etc buy after few monutes, hacker log into my account and again changed password, email, etc. What can I do to get back my account?

I would send Instagram a message explaining this and see what they suggest, Ive never heard of that happening before. Also I know this is obvious but make sure your password doesnt include any full words, is atleast over 15 characters and includes lots of numbers, symbols etc.