They send multiple letters contradicting themselve...

They send multiple letters contradicting themselves in each. One stating they received a check from insurance, the next stating they want me to pay THEM in full saying I m liable and I have no insurance (I do and they mentioned it in the previous letter), and then a third letter with a completely different quote and the first two were sent to a totally different address.
Totally unprofessional, Threatening tones, and violations of the Americans with disabilities act.