You should have disputed the transactions as they were probably not coded as "gambling" related which would be fraud on the part of the company that submitted the transaction.
In your defense, if the processor had coded the transaction properly the credit card issuer would have denied the charge. While you wouldn't have been able to make the transaction, you also would not be in debt right now.
You only have 60 days from receiving your statement to make the dispute.
If you do dispute the charge, the processor would be required to submit documentation regarding the charge transaction and I seriously doubt they would be able to do that since they "misrepresented" the charge to obtain authorization. They have nothing to submit unless they want to admit fraud and lose their ablility to process future transactions through the acquirer.
If they don't submit sufficient documentation the dispute will be resolved in your favor. However, they could come after you for the money via debt collector. Even that would be difficult as the transaction was technically illegal and therefore I would assume void under contract laws(I am not a lawyer though, this is information I gathered through personal research of laws)
Unfortunately, Visa and many banks are still approving these types of transactions even though they are aware of what the charges are really for and people are racking up debt and it is ruining their's and their families lives.
I AM NOT A LAWYER, this is a personal opinion

