RMS+PCCharge+Nova = DISASTER

I have been working with Microsoft for the past 2 months and so far have not come up with a solution for this problem. The situation is as follows? Someone purchases $100 worth of merchandise and presents a $25 credit card gift card. Please keep in mind, that these gift cards look and act just like regular credit cards, so there is no way for any software to distinguish between these cards and a regular credit card. RMS sends a message for approval to PC Charge, which then sends a message to Nova Credit Card processor. Nova returns an approval for $25, which then tells PC Charge. PC Charge now, apparently sends back an approval for the $25, but RMS just sees the approval, and approves the entire order. This means that people can present a $25 gift card and walk out with $100,000 worth of merchandise!! RMS is telling me that Nova and PC Charge should not approve the transaction. They are saying that it should act just like a credit card that does not have enough credit for the entire purchase, where the entire transaction is denied. Nova and PC Charge are saying that it should not be the same as a credit card whose credit limit has reached the maximum. They are saying that it should approve the $25 and prompt the customer to pay the balance. All I know is that I went into Macys the other day and purchased something for $60, and presented a $25 credit card gift card. They took it and told me that I still owe a balance of $35. It seems that they were not using RMS! Microsoft tells me that their own processor, Vital, will deny the whole transaction, if it exceeds the amount of the card. Unfortunately, Nova does not do that, and I have no way to prevent a disaster from happening. I?m sure I am not the only one with this problem ? is it that people just don't realize that this is happening, or is it that nobody is using RMS with PCCharge and Nova ?? Thanks in advance for your response!