Hollard wont remove blacklisting error on my ITC

I have been blacklisted by Hollard insurance by mistake they said to me Two months back and that they will rectify the mistake,I never took it serious until I tried applying for a house and I was told because off hollard listing on my ITC my credit score went down by 9points, I called them ***, they sent me an email saying they sorry and it has been removed, a month down the line nothing,I called again they said I must give them another month it been two months and still nothing my last call was on Friday last week they said today, today I am still blacklisted by them still waiting for their IT, Hollard insurance is not taking me serious my life is on halt because they were *********** and blacklisted me and they did the same thing to my sister and the funny part is we only have a funeral cover with them, my sister went all physco on them and hey rectified and removed the error but me the civil one they Just do not care.