Automatic subscription renewal

I did not renew my cancelled subscription but every year I need to request a refund.
I have protection from another source.

It is nonsense that Avast automatically renew my cancelled subscription

First, I’m an Avast user and not an Avast Team member. I use Avast Free so I can’t speak from personal experience.
Do you still have Avast installed, presumably not) ?

If you able to request a refund. I suspect your cancellation of the Auto Payment Mandate either failed or didn’t happen.

If you log on to your on-line Avast Account - id.avast.com - you should be able to cancel the auto payment mandate.