TransUnion Dispute Issue

I raised a dispute with TransUnion on one of my accounts on my credit report. I have contacted the company of the account, and they confirmed and provided a letter that the account has been settled to me and I submitted it with my dispute to TransUnion. I called them several times in order to get this dispute closed as they have all the information to change the status without any luck. They keep on saying the company needs to contact them and then the company says they did send details through and when I ask for a contact so I can make sure the company contacts the correct person at TransUnion I get told they can't do that. I am so frustrated as I want to apply for a home loan and not until the dispute is closed, I can't apply