Used EV Tax Credit Calculated Incorrectly

I recently bought a used ev that qualified for the used ev credit. I transferred the credit to the dealer. When discussing it with the salesman he informed me that dealer fees were not included in the credit. Consequently there was a portion of the sale price that was included outside of the credit price. That's not right, correct? It is my understanding that everything but state and federally required taxes should be included in the credit. I told the salesman about it and he said there was no way to do it otherwise and that this is how they always did it. It's not a huge amount that I'm missing out on, about $300, but money is money. Can I claim the discrepancy on my tax return? If not, what would be the best way to proceed with this?
Thanks