keep on adding product to increase my installment

on the 25 of February I was surprised to be debited R300 more, when I called to find out they told me that I took on a credit life insurance that I don't know about! I told them that I need it cancelled immediately and till today it is not cancelled! I have another car financed by ABSA I never in my 5 years with them experience this! I want the extra amount debited back in my account and this credit life cancelled !!!