How do I press charges against a business for not providing services promised or a refund of monies provided?

I bought website, SEO, Marketing and other outsourced sales solutions from a company in Illinois. While building the website was a long haul it did get complete, but there were some difficulties that made me 2nd thought continuing with any of the other services I had purchased. I finally decided I didn't want them to start/continue any services that had not been rendered as the quality of communication and the overall output were below my standards for what I was spending. They advised me that certain items had been performed but I come to find out this is false. When I asked for a refund of funds that's when the real problems started. They consistently tried to sell me other solutions to keep the funds which I ended up denying and just requested my refund. As I continued to try and set up meeting to start the refund or RMA process I have been put off, and now have no response in communication. I would like to know what my options are. I spent a total of $16K.