Messing with my ITC

I checked my my statement in February and realized they noted I was in arrears ,when I called they advised it was an error from their side as I have never missed a payment . Guess what Tuesday I checked my ITC report and saw that they had noted that I am behind on payment for February and March I call in and all they can tell me is that they are busy with the query ! I need to apply for vehicle finance and because of their pathetic accounts department and legal department who don't know what the hell their are doing they have put my Itc scoring in jeopardy . This is not acceptable !!!!!! They better sort this out with Transunion and I want proof in writing, I will be escalating this to consumer protector and the ombudsman and every other avenue . How the hell can you make such an error when I have never missed a payment. I want answers !!!!!!!!!!!!!!!!!!