I don’t know who you called but they screwed you. You can buy a converter that will flash to 3500 easily and drive like it’s 2200. Have one in the shop in getting ready to install, and just helped a buddy with the same thing.
It’s not 1980 anymore. Don’t know how many times I can say that. If they told you a 3500 converter was too loose and you ended up with a 2200, you gave up driveability. Exactly what you didn’t want to give up.