Would you mind sharing screenshots of your conversation with their support as evidence to back up your claims?
Just curious, did you use a VPN, use someone's internet, or did someone use your internet? I've seen cases before where the gambler was accused of multi-accounting because of using a VPN, using someone's internet or someone using their internet when gambling at the casino.
Also, their representative hasn't addressed issues posted here against their casino for a while now. I'd suggest also posting a complaint on casino.guru, they might respond there.
I can't recall the last time I seen a stake representative respond to a complaint. I'm not 100% sure but I think they prefer to handle things within their own support system/forum or through an official mediator like CG.
OP have you tried posting in their announcement thread and seeing if someone responds there?