But part of the Stake.com team is still on forums like CapHook and Carrolzinha, they might be able to help this kind of thing to be conveyed to stake.com services directly.
But the OP's complaint will be useless if he doesn't have any evidence of his complaint, because it will only be considered as a made-up story to bring down the casino.
Correct me if I’m wrong but the user that you mention is in-charge only on Stake signature campaign which you can verify their role on the OP of Stake sig campaign thread.
I never saw any user that deals with Stake issue related to players. Stake has their own forum which an admin is more active on dealing with issue like this. So far Stunna is the only user that personally deals with user problem here in the forum but right now he is not active anymore.
Maybe try to ping your manager to see this case.
They are only in charge of their signature campaign on the forum and as far as I know they never logged into the Stake.com thread and didn't respond or interact with their customers, so it might be difficult unless there is some person who can connect them with Stunna, or they are no longer working for Stake, it will be much more difficult to reach the customer complaint service and solve the problem.