Service from Absa makes me doubt their service

I receive a annual mortgage loan statement from Absa.It states that on the 15 of every month i must repay an amount of R8946.22 and an arrears of R2119.48.I make a payment of R12359.59.It shows on credit score that i am in arrears for January and February.I paid this amount in arrears in March.This effects my credit score and i want them to rectify this or take the consequences.