I made a deposit and won some money. I then made a withdrawal that was declined. The reason was they said I had another account with them. I honestly don't remember opening another account. But if so, it was done in error. FJ voided my winnings and closed my account. They are now refusing to refund my deposit(s). This is the email they sent me.

Your account has been found to be associated with multi-accounting and/or association with at least one account (mindtap), which in and of itself is considered illegitimate use of the website. As this is in direct and explicit conflict with FortuneJack's Terms & Conditions, any winnings garnered during illegitimate website use shall be void.
 
Any subsequent Games or Services that you participate in with funds obtained from illegitimate website use shall also be void.
 
Further, since you have been found to have actively participated in illegitimate multi-accounting activity for the purpose of monetary gain, which is in direct violation of FortuneJack's Terms & Conditions, your withdrawal has been terminated.

They should refund my deposit(s) if they aren't going to pay out my winnings.

I have filed a complaint at another forum with FJ is an affiliate of and the owner also says FJ must refund my deposit(s). Yet FJ is ignoring their request as well.

If they can get away with this then this will leave room for anyone who deposits and is in violation of any of their terms. FJ may not only void winnings but steal your deposit(s) too.