I hope that there are some Avast support guys monitoring the Forum - I have raised a ticket (718083) for a refund as I was charged twice for my subscription but have not had any response (been 10 days now). I know how to cancel one of the subscriptions - that is not the problem, I just need a refund for one of them and I can then cancel the auto-renew for it.
Normally avast handles tickets within 1-5 business days.
As the avast support department at the moment is very busy, it can take a bit longer.
Just have patience.
There is no need to wait for the refund before canceling the subscription.
You can cancel it any time you want and will not affect your refund request.