Citibank Credit Reporting Complaint

Citibank Credit reporting department,

Credit reporting company's investigation Investigation took too long California

I have formally disputed an account Citibank N.A. says I owe. The formal Dispute was never communicated or recorded as disputed on my credit report within 30 days as directed by the FCRA. I sent formal letter of dispute in -/-/2016. Citibank said account verified and sent an account statement. Credit report in -/-/- still showed no dispute had been communicated to all - CRAs. I informed them that the account was in error. They continued to report negatively to Credit Reporting agencies. I have since received a letter demanding payment from another company called - A collection company. Even though the account has been disputed multiple times, and they have been told this account is not mine, they continued to report negatively and sold the debt as a factual account to -. I have never had a Citi Costco Visa, nor have I ever applied for one. The only card I processed associated with Costco was an - which was closed and paid as agreed.