All people who are entitled to it will get their refund.
And yes, you need to have patience.
avast is trying to handle everything within 10 business days.
Unfortunately it is not always possible.
This has (amongst other things) to do with people who keep submitting tickets for the same thing multiple times.
With doing so they are cluttering the ticket system and making the wait time for everyone longer than needed.
Do not send multiple tickets or change a existing one as that will put you back to the bottom of the stack.
Ofcourse you will find many post of people saying they did not get their refund in time!
The people who did receive it in time are (normally) not posting that.
If they all would post you will find the fast majority of posts saying they did get their money back in time.