Hi and welcome to Arturia forums.
Sweetwater is'nt Arturia, even if you buy a Arturia product. Is'nt the mail and serial you got from Sweetwater?
Have you tried to activate your product through Arturia Software Center, using your serial? Or tried to registrate your Product on an Arturia account?
I think Arturia had website issues some days, but it seems to be solved now, as it's been some times since the last report about web related issues.
Anyway, you can contact Arturia support directly through your Arturia account, if you need to.