I purchased avast pro in 2016 using credit card and currently I don’t want to renew subscription anymore.
IMPORTANT: I forget confirmation email address also. :-\

Sales: Orders and Renewals - FAQs >> https://www.avast.com/faq.php?article=AVKB24#artTitle

avast FAQ (search and find) >> https://support.avast.com/support/home

contact avast >> https://support.avast.com/support/tickets/new