Unauthorized Zynga Account Charges

An unauthorized transaction occurred on my Zynga account this morning, resulting in the purchase of 10,000,000 gold coins for $431. I had no knowledge of this transaction and demanded a refund as soon as possible. I received no notification of this purchase, and when I consulted with my bank, they advised that such transactions should be accompanied by proper notifications. To be clear, I have not received the gold coins in exchange for the amount charged. I want to emphasize that I take this matter very seriously and am willing to go to court to resolve it. Because of this unauthorized charge, I'm concerned about the security of my account and financial information.