If your account balance on the casino was negative before the closure, then I would blame duckdice, there are casinos like this that don't allow dormant accounts on their platform, so all I can say is that you contact their representative here on the forum, but this is if your issue is not already resolved, since I see that this thread was created over a month ago.
I have same experience like this on popular casino here. I leave a balance on my account and forgot to open for a year + because I become bored in dice game that time. My account is now frozen and inaccessible without any warning through my email.
I just confirmed that I really have remaining balance on my account when I asked the support and they are asking me to KYC before I can claim. Some casino is indeed very strict on dormant account with balance since my other account without balance that inactive for a long time is still accessible until now.
