MailChimp Integration don't allow user data update

We got the MailChimp Integration plugin up and running now.
We can now input e.g:

First Name: Peter
Last Name: Parker

And the user is inserted in our MailChimp list.

But when we input the same E-Mail adress again and change FIrst Name and/or Last Name, those infos get updated in the MailChimp list.

Is there a way to deny changing of user data in the MailChimp Integration plugin? I didn'd find an option for that.

Because it could lead to problems when every user can change the user data of other users by knowing their email adress

Best regard,