A few months ago, I had a negative account sprout up that I don't recognize as mine. To my knowledge, I've never opened this account or held an account with the bank it's reporting on. Even more suspiciously, the account only shows up on one of my three credit reports.
I've disputed the account saying it wasn't mine, but it came back as verified. I did this electronically.
What's the next best step to take in order to get this removed?
It's not uncommon for a baddie just to report to one CRA.
Is the debt yours? If it is, then send a DV if this is a CA or send a PFD if an OC is reporting it. If the amount is in dispute, then contact the OC and get more info. If the acct isn't yours, then contact the police and use the police report to get it off.