The problem is the situation has devolved into a your word vs. his word situation. At first, it was relatively straight-forward: your account was locked and you couldn't do any withdrawals, which wasn't right. Now the casino says you can withdraw your full balance, but you have disagreements on what the full balance actually is. Your screenshots do paint a compelling story in your favor but the operator claims its not the full story.
In all honesty, I would just withdraw the balance offered to you by Winna and then not play there anymore. If you truly believe you are right, you'll have to file a complaint with the casino's regulator, which is something called the
Tobique Gaming Commission. Good luck.