If you forgot the answers to your Apple ID security questions - https://support.apple.com/HT201485
Kappy's user tip: Some Solutions for Resetting Forgotten Security Questions - https://discussions.apple.com/docs/DOC-4551
KingPenguin 02/2015 post - https://discussions.apple.com/thread/6829577?answerId=27660375022#27660375022
Contact Apple for help with Apple ID account security - Apple Support - https://support.apple.com/HT204169
or try this one if your country is not in the list: iTunes Support - Use this form for assistance with account and billing, code redemption, or purchase questions - https://ssl.apple.com/emea/support/itunes/contact.html
Remember, you'll have to prove to Apple you're the owner of the account.