Unfair Blacklisliting

On the 20th of March 2020, I discovered that i have been blacklisted by this company. They have never contacted me previously to tell me about this debt. On the 24th after I have gathered information I decided to contact them on the 24th of March and the gentleman i spoke with could not prove that i have been contacted about this debt he sent me previous e-mails send t with incorrect e-mail address. I want this blacklisting out of my profile. This is not fair