Having a commercial business, it's not good practice to complain about complaining customers here in the forum, when the FIRST mail has been sent on 7th January
The email you sent today, is the FIRST one I ever received from you so, you should take into account that, sometimes, emails might not arrive, being filtered by anti-spam system by ISPs along the way, so they don't even reach out inbox.
And of course, to the benefit of others that might read this, there was no problem with your Serial Number, it was just an issue of copying/pasting from an html email, which sometimes results in the serial number being read with extraneous characters.
As a general suggestion: if you use the "Buy" method, rather than the "Buy on Web" method, you won't even have to manually type a Serial Number to begin with, because the product will activate automatically, and a backup of the Serial Number will be made in your Home folder so, if you keep this file, you won't even need to manually type the Serial Number in the future, when reinstalling.