My question involves a consumer law issue in the State of: Oregon

I posted a few months ago about an incident at a hotel chain where I was accused of smoking in the room, even though I did not, and I was charged a $500 smoking violation fee. I immediately (next day) disputed the charge with my credit card company. This was back in March and they have been doing an "investigation" since then. Apparently I won the chargeback and the charge was reversed, woo hoo right? Wrong! I didn't even receive anything from my cc company saying the investigation was over, however I did receive an email from the merchant saying,

"We received a dispute notice from our Credit card processor in the amount of $500.00 from your Credit card company/bank. We will be taking you to small claims court for this charge, if the $500.00 is not reversed by today, 05/10/13."

I have never done business with such a rude and unprofessional merchant ever! What is my recourse? Can I be sued for disputing this charge? Also I live in California, and I was on vacation in Oregon where this happened, how does this work if I live out of state and they sue me? Can I hire a lawyer for this? I am freaking out right now this happened almost 3 months ago, I did what I thought I had the right to do as a consumer wrongfully charged and now im being sued!

Any help would be greatly appreciated thanks!