Removal of money without permission

I have a vehicle that is paid every month via debit order.I have always had insurance on the car from the start and then absa decides to take out an insurance as well because apparently I do not have one that's right. Sent them all my proof yet they deducted over R900 with my installment. They are now saying I am liable for another R932 that they want to deduct end of February 2016 yet I was told that this insurance was cancelled on the 20th January 2016. I have been on the phone with absa since Mid December 2015 and they still hassling me about money that was never my fault and that I never owed. I have my vehicle for almost 2 years and not one day have I missed payment. Always been loyal and they think *****ing from me is correct. I have all the proof that I have insurance which I also increased to higher payment which takes more money from me as well. I AM TIRED OF IT. They always calling me telling I owe them money but they billed me incorrectly.