I've been through this many times with my first Havanese Sparky. My poor Sparky was completely shaved to his pink skin before Christmas one year.
I actually groomed him myself going forward after that experience! Please do not feel responsible in anyway for you puppy's haircut. If your dog was matted then it was the groomers responsibility to inform you of the status of his coat prior to shaving your puppy. I have learned that grooming is not regulated. They tried to regulate in California a few years ago with Senate Bill 9. It's so important to vet the groomer as to their actual training and experience. Grooming is an art. Tina is very cute and it is just hair that will grow back. Like Scarlett above...I am also fortunate for the last seven years to have the same home groomer. I've learned a lot from her. It would be great if you could find a home groomer in your area for Tina.