The advantage of having someone from stake that is active on the forum can be really helpful in deciding your case. But to be honest, a relatively large and well-known gambling site would not ban anyone from their website without any reason at all. Like what most have mentioned, will it be possible if you could provide a transcript of your conversation between you and their customer service? In this way, some might be able to help in resolving your issue for a speedy disposition of conflict.
Though I really doubt that you were banned for no reason, I am on the hunch that you most probably violated one of their terms and conditions that lead ultimately to your demise.
A gambling site with good reputation just ban an active gambler on stake without valid reason is a shady move and could result in bad reputation so I think stake wouldn't do that that can compromise their reputation that build up over time. Banning a user without reason would change their reputation in a flash. I think op have violated/abused some of their rules/bonuses. I agree with you their that providing a conversation between the customer support and op would make this case a bit easier for us see the situation more clearly.
But op is insisting he dont have multiple accounts which the support told him as the reason why he was banned.
I think he needs to explain his side and show some evidence to back up his claim because Stake will not ban a player without a valid reason.
So what the support says? Is there a way to withdraw the funds?