Mastercard complaint: Cannot Unfreeze Frozen Gift Cards

I recently was a victim of fraud and had $900 moved onto Target MasterCard Gift Cards. The scammer had the card number, expiration date and CVC of all the gift cards purchased so I called 1-800-698-4952 and froze them all before any money was withdrawn. When doing so I created a password with the women I was speaking with so that when I called back to unfreeze them I would be able to prove it was me and was told to call the same number back to unfreeze them. I have been trying to unfreeze these cards for over 2 weeks and have made no progress. The number above asks me to enter the card number, expiration date and CVC before I can get through to anybody but because the cards are frozen the automated operator does not recognize the information and I cannot get through to anybody. I called MasterCard Customer Service and it asks me to call the same number that I cannot get through to anybody on. As said earlier I have $900 frozen on these gift cards that I cannot access and now I am unable to unfreeze them. I want my money back.