Registered a 30 days on my credit report, But i made payment on time.

i opened an account with Edgars, I stated my payment date as the 7th this month i made payment the 5th on their side it only reflected the 9th (i wasn't advised that eft payments take 3-5 days).

I made payment on time the money reflected the 9th on their side they have registered a 30 days on my credit report and refuse to remove it as my payment was made on time.

How pathetic of them to not rectify a mistake that wasn't mine to start with.