I'm not a big fan of disputing, but I would try one of two things: First, I would try disputing via mail or fax (not online) and explain the situation and include any documentation (that letter) and ask the CRAs to delete. Another option would be to send a threatening letter (broad term but I've seen some in here pertaining to bad reporting) to the CA saying delete or else and include a copy of their letter. IMO, I would dispute.