I would ignore and not mention anything discussed here other than 'You sold me FSD, I bought based on FSD, this paperwork shows FSD, but my app doesn't. Please get that fixed and make sure my account is correctly configured so there is no chance of me losing the features.'
Yes! This.
The point that hasn’t been explicitly stated is that the used build sheets/Tesla account descriptions do not match the original build sheet the original owner would have received. It’s a database with codes for options and Tesla updates the labels from time to time. Here’s what my Tesla account says for my 2016 P100D, which definitely does not match what the original owner received on purchase:
But Tesla’s back end DB shenanigans don’t matter. What matters is what you agreed to purchase based on what they told you prior to completing the deal. It may very well be that the previous owner didn’t pay for FSD and that your car was coded as EAP in the DB and that changed when they changed the label, intentionally or not. If someone caught it prior to purchase and told you that’s a different story.
Still, I don’t think they’re going to fight you in this, it’s super clear cut. Along with the warranty, situations like these are one of the biggest advantages of buying used from Tesla. It’s a totally different story on a third party sale.