I've been in the same situation. Appsumo hasn't been serious; they haven't sent any emails or informed the customers who purchased the app. For my part, I feel cheated and scammed. I invest a lot in this platform, and I find the short refund time and lack of notification on their part very unfortunate. In fact, if they were a serious company, they should have issued a refund and notified me of what was happening.
It's been one of the apps I've used the most, but I haven't used it in recent months due to the number of connection issues. I thought it was a temporary issue, especially since Appsumo doesn't inform customers who purchased multiple tiers. I also have two other clients who were offered the tool to purchase because it seemed very good and had promising prospects. Now I find that they feel scammed by me.
I hope Appsumo contacts me and gives me a solution, because otherwise, I think I'll start to doubt this platform. The problem wasn't mine, but APP's. I assume they didn't notify me properly so I could provide a solution.