PEP STORE DISPUTE DEPARTMENT

PEP stores said I opened an account with them of which I didn't and they asked me to complete a dispute form with proof of my ID and send it to them, of which I did. It has been more than three months and they have not communicated with me on their progress with the dispute I made, instead they blocked me and put me on bad credit. When I call their Dispute contact number and make follow up on emails, I don't get responses instead I receive calls from their call center saying I owe them. Can I please get advise on how I can resolve this issue, it is very frustrating.