I've mistyped my client's name while creating iCloud account on his behalf I've mistyped my client's name while creating an iCloud account on his behalf (for example: instead name.surname@icloud.com I typed nmae.surname@icloud.com), and before notice, the mistake, enrolled the account for Apple Developer Program.

Now, I need to fix this mistake but do not know if there is a way. 

Thank you.
I would stop what I'm doing with the misnamed account, and contact Apple Developer Support. Apple's Developer Support contact page is here: https://developer.apple.com/contact/phone/