Once you start the BB load process, it's not easy to cancel without loading something. When you have a GC you're unsure of, try loading $20 first. That way if the GC doesn't work, you can whip out your local bank debit card to load that $20 to finish it out. Otherwise, it's going to take a manager or CSM to cancel the BB load and it's a lot of hassle, like vagrants here experienced.