Not good Standard Ban****!!!!!

On the 25 October 2018 I paid an amount of R1,500-00 to my Standard Bank credit card. I again paid R1,500 on the 26th November 2018. And then again on the 20th December 2018 I again paid an amount of R1,500 before I went on holiday and exhausted my funds. Today I receive a telephone call from the Collections Department to let me know that I am in arrears. I couldn't understand this as I had paid without skipping any payments. The lady explained to me that as I had paid before the statements went out, it shows that I am in arrears!!! I paid all my creditors on the 20th December 2018 and yet Standard Bank is the only one that shows that I am in arrears ... this is ludicrous!!!! What can I do as this affects my credit rating. Not good Standard Ban****!! I would like someone to contact me and adjust this as it was paid, whether it was paid before your statements were printed or not should not affect my credit rating!!!!!!!!!