Arrears - not mu fault.

I have been a client with Absa for more than 20 years and have always made sure that i never skip any payments on any of the products that i have with them. Last week after several sms's and telephone calls from them i was finally able to answer the call and a lady Kedibone explained that my Absa vehicle finance account is in arrears. I explained that i have always paid the account ahead. After some investigation she came back to me to tell me that she checked and that the account was capitalized with my advanced payment and this was the reason the account appeared to be in arrears. The capitalization was done without my knowledge and this caused arrears on my account. I did not ask for a settlement value of the account and this process has now affected only for me to appear in arrears but also my credit score is being effected negatively.