While I can see them being obstinant about adding information for low level account holders, it's still in their best interest to have correct and current information. I'd write them an email and drop some of their own buzz words like "customer service," "customer care," "positive experience," and "trusted by the consumer." Make it seem like they are deceiving their customers by not having the correct ISBN and edition information. The whole quick turnaround, high quality, hassle-free service, attention to detail and customer experience shtick is how they promote themselves. Play to their sense of branding...if the problem resides with them and they know it, you have a shot at getting what you want with no addtional cost to you.
Or, get someone with a merchant account to do you a solid and add it to their database. You might even improve your bottom line if they have lower processing fees and will charge you cost...but it would have to be a friend in close proximity for it to work.