Incorrect information on my credit report / score

I was doing quite well building up my credit score all of the sudden when i check my credit score via my Nedbank App it has dropped by 4 points " ACTION REQUIRED " the information states that i have missed payment on my ON AIR TV ACCOUNT i opted to contact ON TV so that they can advise on the matter to my surprise the agent advised me that as per their records no missed payments or late payment for that matter , Where did Experian got such information which has impacted my score ? called Experian to advised on the matter they always on high volume on calls , sent an email got a response after a week with a list of required documentation that i don't understand.

I'm so frustrated with this matter hopefully it can resolved sooner , the communication from Experian is poor and i don't understand why they are having a call centre because is useless. Can i be contacted please.