If he is calling himself a veterinarian (not that he used to be one but if he is actually stating as fact "I am a veterinarian") and giving you medical advice for that snake, I'm pretty sure it's illegal. Its one thing if he says "The best advice I can give you is to use antibiotic ointment." but if he's saying "I'm a veterinarian and I recommend you use antibiotic ointment to treat the snake." he is giving medical advice and impersonating a medical professional. He may have been a veterinarian years ago, but if his license expired he is no longer allowed to claim he is a veterinarian and give medical advice while claiming to be such. Of course, he may only be able to get in trouble if he's actually PRACTICING veterinary medicine. As in physically treating your animal for a medical issue.

I'm sorry you are having such a bad experience. I hope it works out for you.