Honestly I don't , and I searched however I can't seem to find any but I guess you can do an announcement on Localbitcoins like this : https://localbitcoins.com/ad/151391/purchase-bitcoin-gift-card-code-apple-itunes-gift-card-only-united-states and try to trade your iTunes gift card for BTC  or you can sell your iTunes gift cards on "Digital goods" section for BTC . I'm pretty sure you will have buyers if your rates are good .