Experian does not read emails and update clients credit reports

I had a Standardbank Loan and Paid it in full in Dec 2020. I received a letter from the bank stating that is paid in full. Since then I have sent email after email to Experian requesting them to update their system and added this letter from the bank. Their answer is always...It will be corrected and show on the next report. Today I sent that same letter for a 6th time. It looks like they do not value their clients since it has a negative effect on my Credit Score. Someone is not doing their work and it is just ignored!