Name put on ***** database without proper investigation

Since from last year, I have been trying to get this company that works on behalf of Bradlows or JD group to give me a clearance letter to have my bank account reinstated, on the 26th of April 2022 I sent their agents again onther email, I was called once to say they are investigating and that is after I threatened to expose them, but after that so called phone call and no ending investigations nothing was done, and the most frustrating part is my name is blacklist by thier company and I didn't even sign a contract with them, just asked to see if I qualify for credit then next thing my bank account is closed due to them having put my name on the ***** list , a year later I'm still waiting for thier investigations to be done and no communication from them, this is my last resort because my credit life is getting ruined for something that I did not do.