incorrect information provided

I have received inconsistent information from African Bank, I called last year in August and asked for a settlement amount, the agent sent me a later with the amount, I decided to continue paying the installment with the thought that the settlement amount would obviously go down, last week, I sent a request for another settlement amount and obviously the amount should have gone down from what it was last year as I ha e been paying every month but now I was given a settlement amount that is much higher than what it was last year, how on earth is that possible, when I asked the agent how possible is this, she could not give me an answer but instead advised me to send another email with proof that I was give a lesser amount last year than what she is giving me now, I did that, I emailed proof of what I was sent last year and the amount that I'm given now to show that there is a huge mistake here, the email was sent on the 04.05.2021, I never received any feedback, I then sent a follow up email 4 days later and till today, my emails are not important to African Bank,, how does a big institution like this conduct its business with firstly incorrect or false information and now not getting back to their clients even after they have sent two emails.