Got scam by web developer

Hi, I was introduced to this web designer company in India by a co-worker. They were very responsive and helpful in the beginning, after we've given them $15k (the contract was agreed upon $20k) and saw very little effort being put in, we asked that they fix a lot of the bugs and glitches on them. After some time they still didn't fix the problem and have now completely stop any communication with us and disregarding our many attempts to contact them. I'm in the United States, what are my options? We've worked really hard for our money and saved it for our company and now it looks like we got scammed. I would really appreciate your expertise advices. Thank you.