Your error doesn't have anything to do with mis-typing your Serial Number and the error message is quite clear about what your problem is: you have activated that Serial Number too many times.
Of course, such kind of support request shouldn't be posted on the forum, since there's no more we can say here, given we'll have to exchange informations about your Order, which cannot obviously made in public.
Always use EMAIL support for any request about serial number reactivations. The support email address can be found in your purchase receipt or the "Contact Us" page of this site.