If you can't read parts of the code it's ok. I found information on one of the companies that makes the actual cards. I'm not sure if it's all of the cards but any of them with "fast card" on it: this is the way to recover the missing parts of your code. Things you need - the 10 digit code on the bottom right of the card under the pin code, the store number off of the receipt of which you bought the card, and the remaining numbers/letters on the card that you can see. You can call them from 9am - 6pm EST Monday through Friday. Which is also on the link I'm going to post here. If you'd like you can message them with the information that you need outside of business hours.
http://www.incomm.com/contactus.do?lng=1033