Email from App Store Team - Gift card balance available credit

I got an email from the App Store team, titled "You have a gift card balance" and it read, "You have $xx.xx of available credit to use on the App Store and iTunes. " Is this like a gift card? I did not receive a gift card so I don't know where this money is coming from? I am not sure how to find it on my account and I am afraid it is a scam.

Does anyone know how to find credit on your account?

Thanks :)