Hi, I received a call from Interchex stating that

Hi, I received a call from Interchex stating that I owe for a payday loan to a company called BMG from 2009 and I must pay $600 immediately. He wanted me to state into the phone if i had a debit card I could use if I would be able to pay as if I waited they would think I was stalling and not offer the settlement. I told him yes I had payday loan issues in the past but I had no idea who this BMG was and never had a loan for $600 he said well you know they are loan sharks there are probably fees and BMG probably bought the other company. That Midland had sent me detailed information to collect on this with no response. He said he is an Arbitration attorney for Interchex and I must work with him or there would be papers filed with my county courthouse on fraudulent activity. I told him I needed something validating this debt as I am not just going to pay $600 for something he says I owe to a company I do not know of. He said if I have your social it must be legit. I told him I need to see where they are coming up with $600 who the original company was and what I signed as I do not know what this is for sure. He said his corp office would email me the debt validation letter and that I MUST leave him a VM after work to let him know that I received if and I did not then he will mark it as refusal and continue with paperwork. I got the letter on Interchex Letterhead. Just a write up on the date of 2009 a loan with BMG/Midland amount past due of $600 and amount to be paid in settlement immediately is $600.00. What do I do?? Dont I need some kind of document proving this is my loan and the original amount details etc? I am guessing they are starting the paperwork with the county at this point because I did not leave him a vm but I do not know what to do. All of the scams out there I do not feel comfortable making a payment arrangement with someone from a phone call and a letter from their company stating that I owe a company money from 2 years ago..