Flag on my name

I have had a dispute on the flag on my name for almost 2 years now. All my credits were paid up and clearance letter was issued by my debt councillor. Now I cannot apply for any credit due to a flag still showing under my name, I called transunion last year before lockdown and subscribed to them for assistance on the matter, unfortunately when I call them the phone rings with no answer and emails sent without any respond. I need to talk to somebody that can assist me please I cant even login online...