identity theft

So, I;m 23, and never had a credit card. I have a contract cell phone, but because of my credit, it was limited. So I tried for a credit card a few months ago and was told I was denied threw equifax, but whenever I tried to contact them, they said my information was wrong becuase they wanted information on a insanely large morgage I didn’t have. I couldn’t talk to a human at all. I tried getting a credit card from my current bank and was told it was denied via equifax due to “Judgement or foreclosure”. I’ve never even had a loan! I tried calling the number provided, and got an automated service. I got a PO box address, a number, and the number gave me a website. Should I jsut mail them a copy of the letter and ask for my free report and try from there to correct the identity theft?

EDIT: It’s not ID theft, it’s a $150 debt that was paid off 3-5 years ago, and just needs to fall off my reports.