Cartrack violated my rights

I had an account with CARTRACK Ref ***024SE024SEVDO*** that l cancelled on the last day of June 2023.l had a call from one of their consultants and made a payment arrangement of R50 rand per month fthator the cancelllaton fee of R2600.00 was supposed to be paid on the 31 October 2023 while l am still thinking of sending them theR50 that we agreed on they just debited R1700 from my account.on theb1/11/2023.l furiosly called them and the lady incharge told me that they are not going to reverse my money even if l cancelled and have active payment plan