TransUnion Credit Reporting Complaint

TransUnion Credit reporting department,

Credit reporting company's investigation Problem with statement of dispute Texas

I send a certified letter to the creditor to this addresse ( - - -, - -, T- - ) to obtain a written verification documentation concerning the account dispute. sixty days pass without a response from creditor. I joined a copy of the letter to - - - and asked Transunion credit report to investigate and the result came and state remain .the creditor keep updating monthly the account as charge off. after several call to the creditor they finally said that the account is transfer to - collection agency since - 2012. I wrote to Transunion again asking them to prove how their investigation was done and they should delete inaccurate information on my credit file. Transunion responded that the information is corrected and will remain. I need Transunion to delete or update the inaccurate information on my file.