but for example when I tried to talk them about the situation in their Telegram group, they just simply banned me.
If you complain properly and not doing anything unnecessary, then that acts shows that they don't want to solve customer problem or in other words, shady af.
I think you should find other wallet for your needs, there are a lot of atomic wallet that support quick exchange like Magnum for example.
So, if I send some coins to a wallet and then next day that coin get removed from the wallet without a warning, I should just accept that my coins are lost and I should argue with them about this?
And they not just a wallet, they are an exchange, too.
it looks like others had similar issues with Deeponion coin where the website screwed up but then others seem to have their issue solved recently maybe you have to wait more!
in any case, services like this are always bad by default. not to mention they are always a disaster waiting to happen. eventually they will reach a phase where they can not make enough profit, so they turn into Ponzi (if they aren't already with their 40% profit!) and then slowly start their exit scam.
you should try not to get involved with these things in first place.
I posted there, too, later, btctalk was buggy, had to try 3 times when finally posted
bitcointalk is not buggy, there was a clear error message when you tried posting there telling you that you had to wait 6 minutes to post and that is a rule for accounts like yours that have low rank.
I wrote the email to them 2 weeks ago, they don't even care to respond.
And yes, it wrote to me I have to wait 3 minutes before I can post again, but that would have been my first post 🤔 when the 3 minutes were gone I tried to post again, it said I already posted it but it wasn't there.