Good for you. I am doing the same thing. Even though we in CAnada do not have to pay, they're still obligated to give you accurate results. The problem is, they are accountable to no one. They are rarely questioned by anyone.
In my case, I am starting with a letter to the Lab association {Ontario} and letting them know I have evidence that contradicts them. They had their chance. Next I am taking it up with the federal government health department. With evidence in hand, I will represent a problem to them. Shroom