PREPAYMENTS BEFORE 15TH MONTH AND BIG INSTALLMENTS ...

I have my Woolies Account for many years. I sometimes pay more than my installment and before 15th month. Last year April, I finished working and made bigger payments in advance, yet I was charged the Same interest. My Balance was Zero May/June 2023. Then Woolies had a sale again, and I purchased many items and then Also paid in advance and more than required installment. WOOLIES IS NOW TELLING ME I'M IN ARREARS. AND I SAID I PAID MORE THAN MY INSTALLMENT AND I WAS TOLD I MUST PAY AFTER 15TH MONTH.. AND I'M SAYING YOU ACCEPT MY MONEY BEFORE THE 15TH WHY ARE YOU STILL CHARGING ME THE SAME INTEREST AND WHY AM I IN ARREARS ... AND I'M SAYING CHECK YOUR RECORDS AND RECALULATE MY BALANCE AND ARREARS AND INSTALLMENTS. AND NOW WOOLIES HAS HANDED MY ACCOUNT OVER TO NIMBLE CREDIT SOLUTIONS WHO ARE JUST AS CLUELESS.. Woolies is My only and Favorite Account, But I know need to draw the line with being Exploited ...