Help please!!!!

Hello i recently purchase the avast internet security and i registered my email in order to receive the receipt but i haven’t received any email with my order details so i cant follow the procedure in order to cancel the automatic renewal . i tried this link https://store.avast.com/DRHM/store?Action=DisplayCustomerServiceOrderSearchPage&SiteID=avast but keeps failure i even send an email to support got no answer. now?

https://support.avast.com/article/24/ (Orders/Renewals/Refunds)