I have change my account but still it is locked

Does it say why it is locked?

If a message says your Apple ID is locked or disabled "for security reasons", the support article If your Apple ID is locked or disabled - Apple Support directs you to reset your password as outlined in this article ➞ If you forgot your Apple ID password - Apple Support

If you use two-factor authentication and can’t sign in or reset your password, you can regain access after an account recovery waiting period, as outlined in this document: How to use account recovery when you can’t reset your Apple ID password - Apple Support More detail in —> Activation Lockout Issues - Apple Community

If you cannot resolve it yourself, this article provides country-specific Apple Support contact information for customers seeking help ➞ Contact Apple for support and service - Apple Support