If you believe there's an error on your change of name certificate, you can apply to have it corrected. There's no fee to do this.
You can only apply to correct your own change of name certificate, or your child's if they're under 18 years of age.
If the correction is for a child, both parents need to apply. If you're a single parent, you'll need a court order before applying to change your child's name.
Correcting a change of name certificate isn't the same as actually changing your name. See Change your name.