In as much as you are trying to prove a point op you too must come with a clean hand. You said they told you about opening multiple accounts and if we are to go by that, it seems your ip has been used to open an account with them before or possibly you might be using a public internet service which might have prompted their actions against your account or did you use a VPN while login into your account? From the post you made it clearly states so maybe as a result of that, you will need to prove beyond reasonable doubt you did not default their policy, terms and conditions. However, there is no proof here as I tried quoting you post so that the pictures could be viewable but to no avail. I would suggest you use the imgur or imgbb.com to make upload of your proof.
We must see a warning sign about multi-account, right after we register. Now if the OP still continues to deposit, there is nothing to be blamed here but him. When registering to any site, it will be best to not use a public internet because we never know what if the IP is already been used for illegal acts?
There is also a tendency that the owner of that wifi will sniff our login credentials and hacked your accounts.
If we already have created our account before and successfully use it, what's the use of using a VPN to login? A casino can ask us a KYC if they detect us and if it's against the rule but we can always complete it if we want to recover our account.