6

It is not scamming at all.

As user you agreed to the automatic renewal when you bought avast.
During the purchase and at any time after that, you could have disabled it.

It doesn’t matter if you have avast installed or not, you pay for the subscription.
Just as with a magazine.
It doesn’t matter if you read it or not, as long as the subscription is there you have to pay for it.

Customers are notified 3(?) times by mail before the automatic renewal takes place, giving them enough time to disable it if they want to do so.

The people form avast can and will answer if you have submitted a ticket.
There is no need to show a email or a bill as the people from avast can see the payment details (and other things) if you provide them the information they want/need.