Product: Vehicle loan or lease

On XX/XX/2021, my husband and I completed a joint request for pre-qualification from CapitalOne. Shortly thereafter, we received an pre-qualification letter in the mail stating we were pre-qualified. Their XXXX website had to be used to determine how much. We found out we were pre-qualified for up to {$20000.00}. 
We spent a couple of weeks working on our auto insurance because we were adding a 3rd ( young ) driver and need the extra car. Many calls with VIN numbers to see what rates would be for the young driver.

When we finally narrowed it down to two cars on XX/XX/2021 ( the pre-qual is good until XX/XX/2021 ), I was unable to get the payment calculator to work. 
First, I used the chat option on the XXXX website for help. They told me I had to enter a trade-in vehicle amount in order to view payment, APR, down payment, and terms. So I called XXXX to speak with a representative. She told me that I had to have a trade-in in order to get the payment calculator to work. 
She transferred me to a supervisor, who, after nearly 30 minutes of conversation, told me that we were not eligible for an auto loan with CapitalOne. That no amount of down payment applied would get us a loan. We qualified only if we traded in one of our existing two vehicles. 
We only have 1 auto loan for less than {$5000.00}. We're currently using less than 20 % of our available credit. Our average credit score combined is XXXX. We have over $ XXXX equity in our home and it's appraising for DOUBLE what we paid for it. We have no missed payments or bankruptcies. 
I'm upset that for nearly 2 weeks, I've wasted my time looking on their website for a car/dealership which they approve of because we were told both in a letter and on the dashboard of our account that we were pre-qualified for a loan up to {$20000.00}. We set up appointments to test drive the vehicles! 
Our reference number for the pre-qual : XXXX. 
No where does it tell us, not on the letter communication NOR on the dashboard, that we had to trade-in because we're not qualified for TWO auto loans, regardless of the amount of EITHER loan. 
I asked about putting down XXXX % as a down payment and we are still NOT qualified. Yet, according to the paperwork and their online account, we are. They are not disclosing the terms in which we qualified and to say you can borrow up to $ XXXX is no small feat, when in reality, we do not qualify AT ALL. 
Here 's part of the letter we're supposed to take to the dealership : " Amount Financed Restrictions : For new and used vehicles, the minimum Amount Financed is {$4000.00}. Your maximum Amount Financed may be based on income, key credit characteristics, the vehicle you are purchasing, the details of the financing deal, and/or the specific dealership from which you purchase the vehicle. The Amount Financed may include the vehicle sales price, tax, title, licensing fees, dealer fees, and any optional products like service contract and/or extended warranty that you choose to purchase from the dealer. '' I've uploaded a copy of the letter as well. 
If you read the letter, you'll see that it says " may '' and " some ''. No where does it say " required '' or " contingent ''.