You disputed via a CRA.
There are thus two "investigations" involved, both of which are required under thee FCRA to be "resonable," and either of which you can contest in court.
The CRA is required to forward a copy of your dispute to the furnisher for their required reasonable investigation and response back to the CRA. You can challenge the reasonableness of that investigation, and thus their determination and response back to the CRA.
The ultimate determination of the outcome of your dispute, however, resides with the CRA, who is charged with conducting a final "reinvestigation" of the dispute, or which the response received from the furnisher is but a part. However, in most situations, the furnisher's response is the only basis upon which the CRA conducts its final determination in its reinvestigation, which is send to the consumer in their Notice of REsults of Reinvestigation.
If the CRA obtained a response from the furnisher (which you can determine via a Method of Verification request), they will rely upon that investigation.
You would likely need a fairly strong case of the CRA ignoring what you consider to be factual documentation in support of your assertion of inaccuracy in order prevail in a civil action against the CRA for improper conduct of their reinvestigation, but you can certainly bring civil action against either the furnisher or the CRA.
