I see. Thank you for the additional information, James.
The Equal Opportunity Credit Act prohibits discrimination in lending on the basis of age, so a denial would typically violate that federal statute.
Since you otherwise appear to be well-qualified and were pre-approved, and the lender did not provide a legitimate reason for denying the loan, you may wish to file a complaint with the US Department of Treasure, Office of the Comptroller. Here is a link to their site which summarizes the law on this issue:
Here is another link to their site to file a complaint:
Or you could retain a local attorney to represent you in pursuing legal action in this matter.
I hope this helps clarify the situation for you. Please remember to rate my service once you have all the information you need. If you have any other questions, please ask me – I’ll be happy to respond. Thank you!