Nedbank last time using u

I have been dealing with Nedbank they approach me for a credit card i almost never use it and if i do i pay on time end September even before i transfer an amount to Nedbank which they then reply that I have paid short and i immediately contact them and ask why it is short they in return said i paid Shirt with just iver R100i paid another R500which means i am not in arrears i also asked the agent if this will reflect my credit score for my score is iver 711 on my credit score after they say it wont have a effect on any thing now today i received my score and ques what it has been effected all over my credit profile why Nedbank pay my last on the card today and then i will never use them again remember they approach me for the card to build my credit i made contact twice today just getting transferred NEDBANK what is your way forward to fix my profile