Old mutual continues to make my life a living hell

I recently bought a car and took up the Old mutual car insurance. I have never missed a payment and had been reassured that even if it were to happen that I skip a payment it would not affect my credit profile, However, a week ago an application I had done was declined due to a missed payment on my Old Mutual car insurance!!!!!!! I litterally cannot apply for credit because of this, when I contacted them I was reassured that there is no missed payment and that everything is in order YET MY CREDIT SCORE HAS DECREASED BY 19 POINTS. I have never received the best service from Old Mutual and they level of incompetence is increasing. My work is greatly affected as I need new glasses - the credit provider will not consider the letter that Old mutaul gave me as they only approve applications according to the information on my credit profile. I truly regret taking up any products with old mutual.