Incorrect Listing on ITC (TransUnion)

I have been trying to sort the issue that there is an incorrect listing / information about my account on TransUnion. I have send emails, contacted the Call Centre and to date - NO REFERENCE number, NO FEEDBACK, NOTHING and the information is still incorrectly recorded. None of the Agents had a glue on which department lists or updates information with ITC. I need this issue to be sorted ASAP, as this is affecting my Credit Record badly.