Incorrect Listing

I have a new listing on my bureau report that I owe Zone Fitness. I DO Not owe Zone Fitness and now i have an adverse report on my credit report. I have emailed, no response to emails. i have asked countless times for what I owe, no answer as to what I owe them for, rather that I just that i owe. Surely one would be able to generate a statement from what the amount stems from? If Nimble does not have an answer on the screen in front of them, then how does the client you are calling know either? this account was CLOSED 2017. My son used the gym and we closed the account as the area it was in became unsafe and my son as nearly ******. Can Nimble remove the incorrect listing on the credit bureau report please.