I have also had small problems with my Volumebuy AA purchase. One of my credit cards was billed an amount in excess of what was authorized. The other card I used (personal vs. business travel) was not billed at all. My guess is that in the attempt to ship both orders at once, Volumebuy simply combined the order. However, the customer service rep realized what had happened almost immediately and was correcting the error today.
On the plus side, Volumebuy did pay for UPS 2nd day air to get the AA certs to me and I will be using them later today to make a purchase.
rich