Well the so-called, "Technical expertise", you've been given is a line of bull-feathers. You've been given conflicting excuses as to why the paint is so bad on your car. Contact Toyota Inc. and inform them you want a Toyota Zone Representative, an actual employee of Toyota Inc. to look at the car. Period. If they are unwilling to help you, inform them that you then have no other alternative than to seek out legal assistance regarding this matter, (that might make them change their mind about having your car looked at by a Toyota Zone Representative). From that point on, they are now the enemy, from a legal perspective and you should not talk to them without the advice of an attorney.
Next, find a good attorney who will help you. Most attorney's will provide a free initial consultation and many will work on a contingency basis where you don't have to pay anything up front.
The Better Business Bureau can also help you, as well as the Office of Consumer Affairs. You have a lot of consumer rights on your side. Use them.