The FFL didnt initially know the reason for the denial - I was trying to summarize the situation because some wouldnt read through it and address the questions in the post. Thanks for the insight you've provided so far.
For more detail, the situation went like this:
An FFL was offering a limited time promotion of a two for one firearm deal, which required customers to pay up front and the firearms would ship from the manufacturer and be picked up later that week. The customer paid and was added to the list, but no background check was done at that moment.
On the day of pick up, the background check was done, and the customer did not provide their SSN on the form because they've purchased firearms in the past without it, and they have no criminal record or reason for disqualification, so they thought they were fine. They also don't like their personal info just floating around. The NICS came back denied. The store clerk provided the brochure with the website and NTN on it, and said they could find out the reason for the denial there.
Customer goes home, begins googling as well does the initial inquiry on the website to find out about the reason for the denial. In between that, based on whats being found info-wise online, the FFL is called and asked about the possibility of running the background check with the SSN, as well as questions about the timeline for the appeal, etc. The clerk then relates the message about if another attempt is made to purchase a firearm within 30 days, the authorities will be notified. Customer asks the clerk how long will they retain the firearms while this issue is being resolved, and the clerk tells them they'll have management follow up with them.
The reason comes back from the database which clearly indicates a case of mistaken identity, as it references conviction/prison sentence that doesn't apply to the customer. Customer starts the challenge/appeal process.
Customer doesn't hear form the FFL for two days, so when he calls back he mentions the appeal process and asks again how long the firearms will be held. Clerk says they're not holding them and that only a refund will be issued. Customer takes issue with this. Later on a manager calls the customer back and says that while they can't hold them, once the issue is resolved they will offer some type of comparable deal (basically trying to be more understanding and make it right).
In between all this, the customer learns that the appeal process involves fingerprinting and documentation, but also learns about the benefits associated with the LTC, and how once its attained it is not necessary to do a background check for every purchase. They reason that they might as well go through the background process associated with LTC since they'll only need to do it once. However, they are not able to get a straight answer on if there is an issue with moving forward with the LTC process while the appeal is going on or the incorrect info is on the background check. LTC Instructors are contacted and some say one thing, whereas others don't know. Attempts are made to contact lawyers that advertise they are specialists in firearms, but those attempts are not successful.