activation key sent was invalid

For some reason after purchasing premium Avast, it was corroded and as a result my whole system became infected with all sorts of problems. After following directions for deleting premium avast I received an updated version. However, upon getting the attachment for the activation key I finally opened it with notebook and found there was no activation key only a license file and certificates. Have tried several times to message support but there is no reply. >:( >:(

Corroded … your car Corrode, files corrupt

my whole system became infected with all sorts of problems.
And what would that be?

Are you inserting the license the correct way?

Insert license https://www.avast.com/faq.php?article=AVKB88#articleContent

FAQ videos https://www.avast.com/faq.php?q=video#searchForm