Very unhappy with this place. They processed tests...

Very unhappy with this place. They processed tests for my clinic back in March of 2017. I NEVER received a bill or notice from them that I owed them money for over 2 years!! My address has been the same for years so it s not like I would have never received it because of them having the wrong address. So instead of receiving anything from them, I just received a notice from a collections agency for $84. Seriously?! If I would have been contacted by them initially I would have paid the $84 2 years ago!!!!