Product: Debt collection

On XX/XX/XXXX I was alerted through XXXX XXXX of a debt collection that was reported on XX/XX/XXXX to my credit report from national service bureau from an old XXXX XXXX XXXX XXXX XXXX called XXXX XXXX XXXX  that I closed my account with and paid my balance a long time ago and ever since I have not received not a call, email or mail from that XXXX XXXX XXXX XXXX  and national service bureau that I had a debt that I owe. I was informed through XXXX XXXX today on XX/XX/XXXX about this supposed debt collection. How could they not inform me before reporting to my credit report ( XXXX XXXX ) without my knowledge and destroying my credit score if my phone number and previous addresses have always been all updated??! 
I make sure I pay everything on time and constantly check my credit report for any debts I owe and I have never had any debt report from national service bureau until now XX/XX/XXXX. I was never notified from National service bureau that I have a suppose debt with them they never informed me, notify me, not try to get a hold of me before sending it to credit report to credit wise. 
I tried calling original lender XXXX XXXX XXXX but they are out of business both of their locations I tried calling all the numbers provided on XXXX and they are all disconnected numbers I tried to go on their website and it said website not found I tried sending emails to some of the staffs but the emails would get returned as invalid so I can not even get a physical receipt that I paid everything off with them so I called the number that was provided on my XXXX XXXX  for debt collection for national service bureau to ask why is there a debt for something I do not owe, and why is it just now after almost XXXX  years later being reported to my credit report without my acknowledgement about this debt! The first call was not answered and was told to leave a voicemail I left a voicemail and then I called again an hour later and was able to get a hold of someone who asked me for my name date of birth and phone number but she could not find the debt account under my name and I told her what can I do because its showing on my credit report on XXXX XXXX and I know its an error because i dont owe anything to XXXX XXXX XXXX and I need this to be taken off my credit report she then told me she will transfers my call to someone else I was transferred to a guy he just asked for my first and last name and then quickly told me I owe them XXXX XXXX  and I explained to him that it is a mistake my account with XXXX XXXX XXXX was closed and I dont owe them anything and he said thats not what I have here so you need to pay I told him it is a mistake to please help me with the information to contact XXXX XXXX XXXX but he did not provide me their contact information and said its not his problem and I need to pay or it will impact me negatively I told him that is not correct I need to file a dispute but he said okay send your dispute to our po box mailing address and I will deny your dispute because I have documents about your debt I felt hopeless because whatever documents he has I can not confirm if they are legitimate from XXXX XXXX XXXX because they are out of business and no way of contacting them and he would not provide me with their contact information and I felt threaten by his comment that he will deny my dispute and theres nothing I can do about it, he was very rude and not understanding or willing to help I told him is there payment plans because I have never experienced this sort of customer service ever in my life I have XXXX and XXXX from XXXX XXXX XXXX XXXX XXXX  and this guy from national service bureau was raising his voice and being rude when I asked if he can help me because it is an error. 
When I asked for if they provide payment plans due to fear of having this on my credit report not being able to confirm if its legit or not but fear of my credit score going down he quickly changed his tone of voice because he assumed I was ready to pay I told him how much is the lowest I can do for payment plan his tone of voice changed again to as if annoyed then was being pushy to me about the payment needs to be high or they will charge interest rate and I wont be able to pay it off and I know you want to purchase stuff and you wont be able to purchase stuff until you pay this debt off so I should try to pay the full amount now. I told him I will need to call back later he then proceed to tell me they close at XXXX and I will need to call back before XXXX I told him okay and then he said you have to call me back to my direct phone number which is XXXX XXXX XXXX but then he said you have to call me back soon because I am in eastern time and youre in XXXXacific time and my time of the call was around XXXX and he said it was already XXXX where I am at so I told him I can try call him back tomorrow because I wont have time later because he will be already closed he said okay I am marking on your profile that you will call me back tomorrow and if i dont hear back from you your profile will be flagged in rude tone and I told him Ill try call you tomorrow.

This whole situation has made my health condition worse that causes me a lot of stress and XXXX throughout the day because I was not able to receive help and the original lender is closed permanently and no way of getting a hold of them to sort this matter out it made my health condition worse that affected my XXXX and I know I dont owe anything and was never informed about this supposed debt. 
I check my my other credit report ( XXXX credit report account ) and I could NOT find this collection debt from national service bureau on my profile so I was very confused and skeptical and believe its a scam because I did more research on national service bureau and found reviews on XXXX that people had similar experiences and claim that they are scams and have been reported to police and also the CFPB And XXXX and credit debt govt departments and I am not able to rest and think until this matter gets solved. Please I need help reporting them and believe it is fraud and Im not sure what to do because this would be the first time this ever happened to me. I will try and find my cancelation papers and final payments with XXXX XXXX XXXX  if I can but its almost XXXX  years ago Im not sure if I still have them. There is many complaints about them scamming people and harassing them.

I can also provide pictures from my other credit reports that there is no debt I owe to to national service bureau to CFPB. There is reviews of people who have been scammed and paid the supposed debt and when ask for receipts for completed payment with national service bureau they have told them no and hang up on them so they can file a report on them and I dont want to be a victim of that too please help!!