Gift Card code has not been properly activated!

Hello there. Right today (Jan 21, 2017), I bought 14 iTune Gift Cards of $ 15.00 USD each one (the store didn't have $50 nor 100); I started to redeem all codes Using the cam, but one of them gave me the following message: "The Gift Certificate or Prepaid Card code you entered has not been properly activated" followed this, it says: contact iTunes Store customer support for assistance; which is what I'm actually doing here. Help please!!! Thanks ahead!