Complete Payment Recovery Services Accusing me of overdraft to an account that was close long time ago Tuscaloosa, Alabama

I was accused by this company of overdrafting a certain amount of money in an account I closed long time ago and I don't remember using that account again. When I ask them to provide me proof where this amount came from and what date it was drawn within 30 days, they cannot provide me anything and after several months to a year they are insisting me again to pay that amount and they are threatening me if I won't pay and send them the money,they will report me to my personal credit file and to the national check verification databases which will affect my ability to obtain credit or open other banking accounts. This company have been threatening American citizen by collecting money  and threatening them. They need to be stopped. This is another modus operandi of earning substantial income from innocent people.