I did call them and it was a nightmare. First they wanted to know how and where I got this code because they knew nothing about it and acted like I was trying to pull something (first person I dealt with was very rude). When I talked to a supervisor she also knew nothing about it but she was nice and put my on hold to try and find someone who knew something about this. After being on the phone with them for over 45 minutes, they came back that it was a one time use code and I had used it and could not forward it to the now lower price flights I was changing to. So after losing the $25 per person code (x5 people) I saved a big $7 but I do have better times. But I have since gotten another code that I will use if prices come down again.