How to track Apple Gift Card spending and retrieve stolen funds?

I was victim to a "technical support" scam trying to get my IMac to work properly. I stupidly, embarrassingly called a number on my phone listed as "Apple Support" that wasn't. I fell under the scammers' spell and ended up purchasing two gift gift cards. I now have a new credit card and have saved all the information from that day. However, Citi denies the fraud dispute. Does anyone have an idea how I might get the $ back? I have to think there's some way to track where the gift card was spent? Many thanks for ideas/help

[Re-Titled by Moderator]