Recover Hacked Instagram Account

My Instagram account has been hacked. I need help to recover it. Details: - I cannot access the email or phone number linked to the account. - The hacker changed my email or phone number. - I still know my username but have no old proof of ownership... (Budget: £20 - £250 GBP, Jobs: Account Management, Computer Security, Internet Security, PHP, Security, Social Media Management, Technical Support, Web Security)