Product: Debt collection

I recieved a letter from Diversified Consultant Inc. last XX/XX/XXXXstating that i owe XXXX XXXX XXXX amounting to {$1200.00}. And i do n't remember any balance from XXXX XXXX XXXX so i called XXXX XXXX XXXX collection department to verify it i gave the account number written from the letter i recieved and they ca n't find any account like that and i gave my SS # to them just to check if a have a pending balance with them and nothing showing on their system that i owe them anything. So i called diversified i spoke to XXXX initially i told him i want to clarify this account because i called XXXX XXXX XXXX prior to calling them and they ca n't find any records under this account and base on XXXX XXXX XXXX records i do n't owe then anything so he put me on hold and someone name XXXX ( manager ) is the one talking to me now he 's approach is kinda arrogant he 's saying that i just need to pay {$600.00} and he will close the account and i told him i have no problem paying it if i really owe something but my question is i do n't remember that i owe XXXX XXXX XXXX any amount and i told him that i verified it with XXXX XXXX XXXX and the account number is not showing, so i asked XXXX to give me the right number and he said that that is the right account number but the account number from the letter is 12 digits and XXXX XXXX XXXX need a 9 or 10 digit account number. And i told him before i pay something a have to verify it first and he said XXXX XXXX XXXX ca n't give me any information anymore because they are washing their hands!!??? i dont know what does he mean by that? and i even asked XXXX if he himself can call XXXX XXXX XXXX to verify it and he said they do n't do that and he just keep talking trying to intimidate and scare me by telling me that i owe this amount And he is insisting to just pay {$600.00} to close it. He said that this account is since XX/XX/XXXXand i asked him why just know i 'm recieving a letter and he said because i did'nt give them my updated address and i told him i stayed in the same address from XXXX and i just move to a different state last XX/XX/XXXXso why I did'nt recieved a bill from XXXX XXXX XXXX or a letter from them during those time why now and how and where did they get my current address and he did'nt answer to where did they get my new address. Now i 'm scared about my safety and they are violating my privacy because i 'm just surprised that they have my current address on their records to think between XXXXnow in this new State that i 'm leaving i moved 3 times now i bought a house and just moved in here less than 2 months they have my new address so it 's kinda scary and it 's bothering me how and where they get this new address to think that this is a new community and it 's not even showing in XXXX map if you search for it ..so they have the capacity really to get your personal information just like that invading your privacy and who knows what other information they have about me so it 's bothering and stressing me a lot worrying about my safety and security. So now i do n't know what to do with them ..XXXX even saying that XXXX XXXX XXXX changing their database that 's why my account is not showing anymore i mean how did he know that? I do n't want to pay this amount that i do n't even remember that i owe and i just do n't want to pay it by what a stranger just telling me!!