Transunion no longer trustworthy!

I am afraid the once mighty Transunion has fallen. They simply do not have their house in order. For once I understand why many credible institutions like banks no longer even bother to check with Transunion. I wasted almost 6 months trying to get my credit history on a good footing with Transunion, because that is who I have been with for years. Not good anymore, only realised this 2 weeks ago! Had I known I would approached Experian or even Vericred or Clear Score. Since Dec they cannot fix my Nimble account to reflect a correct instalment and balance, even when Nimble has sent them a letter with correct information and they have confirmed this to me. Had Nimble just updated Experian or Vericred, I would have been far now. Since Jan 19, they have been telling me of a system error, escalating the case for a 1000 time. I wonder what else is incorrect in my credit report with them! It is just bad with Transunion now...I have called them almost every week since Jan 19, no resolution, system error, escalated, all that I receive!