Billed for items not showing in Subscriptions

I have been billed for Anti-track Premium even though this is not appearing in my list of subscriptions. I am not getting any reaction from Digital River (the billing agency). How can I get my money refunded, I do not want this product?
Today I also started a 30-day trial of Driver Updater. This item is also not showing in my subscriptions listing. How to I cancel this?
NOTE: By law it is required that the seller provides a method for cancellation equal to the original purchase method. In my case this means I need to be able to cancel via Internet, but I only see a telephone number to call.
Thanks, Rene

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