This is really concerning, indeed! I'm not sure I've seen such condition on any other casino (calculating the withdrawal limit based on the deposited amount). What would make things worse is if they have a high wagering requirement on deposits.
I just read their ToS and there is no mention of those limits.
8bet.io have an active ANN Thread ... on this forum and their representative is very active, so you can send your concern there.
I doubt he will ever get a reply from their pr. The account they use to post updates on their Ann thread seems more like a bot and it never interact with other members or address their concerns.