National Credit Adjusters, LLC Debt Collection Complaint

National Credit Adjusters, LLC Debt collection department,

I do not know Cont'd attempts collect debt not owed Debt is not mine South Carolina

I get monthly credit reports and this month i have a company turn me in collections and i have never heard of the debt, I called the original debt ( - ) holder listed on the report and they kept me on the phone for hours then hung up and i called back they stated it was sold to another company so i ask for the information they sold and said they could not give me that but did give me a company name ( National Credit adjustments ) so i called them and told them and they said that it was sold to another company ( - - - ) but refuse to give me any other details i ask why i was not sent a letter or invoice and he stated that if i paid my debts things like this would not happen, So then I called the - - 4 times and left a message but get no return callNational Credit Adjustments is the one that reported it to all three credit reporting agents, i want proof of this debt