Company's dedicated customer service numbers are completely automated. There is no way to speak to a representative. Numbers are busy with no option to leave a call back number. On line dispute reuires a two-digit ID number which appears nowhere. They were previously sued for failing to provide reasonable access as required by the FCRA, but it appears they've done nothing to change that.
I disputed a state tax lien by mail with enclosing a date stamped document from the court stating that the lien was canceled/satisfied. (I offered to also send documentation that the tax was never owed, if needed.) I received a letter back stating simply that they investigated and the unsatisfied lien "remains." I have tried the entire day to find any number for any office at Experian where a live person will answer. That includes even Investor Relations, Press/media number...everything. You cannot get them and, as noted, trying to dispute or check the status of a dispute requires a two digit "ID" which appears nowhere on the report.