Pathetic service

It's been two months going for three. Every month I need to email Xavier at Standardbank about my Personal loan account that's installment shows R7217.00 incase of R2405.00 that is ruining my credit score at all 4 credit bureau's kindly update this once for all cause now I have send emails monthly in regards to this incorrect information reported to the credit bureau. I did not sign up to pay R7217.00 per month but R2405.00 I want this fixed once and for all. I can't keep having to send emails per month to have it fixed.