There have been many similar cases in the past, and as far as I can remember none of them have been resolved positively for people who have duplicate accounts from the same IP address.

It's not "illegal" but it's against the casino rules. I think that some casinos allow this (or don't have anything against double accounts), but anyway, before you decide to make a new account from the same IP to avoid some restrictions you should take a peek at their ToS or contact support agents and ask them if can you do it or not. But you decided to act on your own and you got into the problem... I hope that you will be able to withdraw your deposits, I think it's the max you can get back from all this.