Made me pay for stock don't have & won't refund

We ordered stock from them and where told they had. 2 days of persistence we find out that they did not have the stock however took my money. Now they refuse to give my money back as they apparently sent me some stock I never ordered and want me to return it. I am personally going to drive 500km to deliver the stock I never ordered and still the do jut return my mails or calls