Help me solve this

You created the Apple ID "Qisaotic" - "it" says what it says because it can do the math on today MINUS your birth date

Since you have Qisaotic ,I am confused as to your problem.

I have asked that your duplicate post be removed... bad form to do that.

You cannot change your date of birth, no matter how old you really are... I am almost 63 and I cannot change mine either!

Your "mistake" is permanent, so your only option is to start over and be more careful.

If you are actually under 13, you are behaving badly.