Collection on my credit report

So, I got sued by capital one because I didn't pay my credit card back because I fell on hard times. I showed up to the court but their lawyer didn't so the judge ruled in my favor and said I didn't have to pay them a single dime. Well now they have sold my debt to some other blood sucking debt collector and they sent a collections thing to the credit bureaus. What can I do to nip this in the butt and tell those idiots to buzz off?