Ackermans not recording my payments

I keep getting reminder about missed payments which is not fair since my payments are made on time and I have noted that you even indicated on my credit record that I paid late last month which is not correct. What account details and reference must I make for you to know that I have paid? Today I received an sms claiming my account was not paid for the month of August and yet I paid on 23 August. During the month of August, I kept receiving calls and correspondence claiming that I had not paid my account since May 2021. Which was not the case, and I sent proof of payments more than once. This is unfair.