What the hell!

I was contacted last week by CCR because I have an old payday loan I never paid. They said the same #$&* to me. Going to take me to court, convict me of fraud/writing bad check, garnish my wages, take my taxes. But they wouldnt allow me to mail in a payment and wouldnt provide any proof that they purchased the debt from the company I owed. Everybody told me not to pay so I didnt. Well yesterday I get a call from a different company RAS, saying that they own the debt and I need to pay them. So I have two companies trying to collect on the same debt and both call each other a liar. WHAT THE HELL!