False Information updated in CIBIL

I took a Barclays bank personal loan of Rs 1 lac, in year 2008 which I paid off in full in 2012 without defaulting via monthly EMI's. However, there was a credit card fradulently registered in my name using my details, with Barclays in 2009 and used, which I wasn't aware of till 2018 when I took my CIBIL report for the purpose of auto loan. Later I got to know the account was purchased by Phoenix Arc (PARC) and they kept calling me and asked me for repayment which amounted to Rs 26,481. I do not know what is the principal amount and how much is the interest. I repeatedly informed I had never had a credit card and this error needs to be corrected. My CIBIL has been affected since. I paid off my auto loan in full without defaulting in 5 years via monthly EMI. I have one credit card with ICICI which I use regulalrly and pay in full without defaulting. I sent emails to Kotak bank/PARC as Kotak bank owns PARC but no satisfactory response, other than they asking me for my PAN details and CIBIL report which I sent them. I registered a complaint in banking ombudsman but I got a response saying that since PARC is not registered with them they cannot go ahead with my complaint and closed it. I want this error to be cleared and my CIBIL record to be cleared. What must I do? Should I proceed legally? Please help.