I was never treated by them, but they still went a...

I was never treated by them, but they still went ahead and billed me TWICE! They just sent a final warning which was actually the first time I'd heard of anything concerning still owing them money! I was sent there by mistake, and ended up not getting treated, but still paid my bill on the spot just to be a good sport for them taking a minute to check me out. Now two months later they're saying that I still owe them money and it's going to be sent to a collections agency? As far as I'm concerned this is a shakedown operation hiding behind a medical office! Shame on them for trying to charge anyone for not even being treated!