ABSA Vehicle Finance Fustrating

I had a vehicle which was finance by ABSA vehicle finance, in 2015 the vehicle was repossessed

I was handed in for Debt collections (Nimble collections)where I made arrangements for the Amount of R1000 to be debited from my account monthly

The month of August Nimble collection took R1000 from my account and ABSA finance went in and take R16 000 from my account without any arrangement, If nimble collection is able to collect R1000 successful monthly why is ABSA vehicle finance still goes into my account without my permission and take all my salary

I called ABSA Car Finance a couple of times they provided me with an email address to send my complaint until today no one has given me feedback or refunded my R16 000