Some countries only require rapid antigen, and those are generally 1500 baht. Check the requirements where you are going, and then call Dr. Donna... :)
I get it... the system is less than ideal, but they aren’t going to try to figure out who gave you bad information and make them pay the fine... Thai bureaucracy is truly a wonder to behold.
I think the popular saying is, “Welcome to the land of smiles...” 🙂
I had the same thing happen when I ordered a battery from overseas... I determined it was not worth the hassle to get licensed as an importer/exporter to save six dollars over ordering locally... Amazon seems to have a good system worked out that is pretty smooth, so if you really need something, and it qualifies for shipment to Thailand, that may be an available option in the future. As stated above, how it is shipped and what is on the waybill will determine how customs wants to handle it.
It's fine to hear most people tell it... I was saying all of that for the people saying what a shit holiday it would be to spend two weeks in quarantine. :)