As a paying customer for several Avast Products, I suppose Avast must offer compensation to any paying user who got affected by this situation.
You made a fortune on selling our data and capitalized on our trust. Now it's time to give back. Otherwise, lawyers might be involved, and you might end up facing a collective lawsuit. I'm not sure how these things work in the EU, but here in the United States, you can really get your ass kicked.
So, while it's not too late, I seriously advise anyone from Avast who is reading this forum - show this message to your manager, and ask to show it to the next manager, etc, until it gets to the very top. But in any case - you have really dropped the ball, and I'll be quite interested to see how you will try to make it up to all of us (paying customers), I'm sure that there are millions of people around the world paying for Avast products.
Good luck.