Nrb Risk Solution debiting my account ********ly

On the 26th of July 2023 I received a call from Bongiwe Khumalo from NRB Risk Solution regarding the account I was behind with, We agreed on the total amount owing and made a payment arrangement of R250 a week from 28 July 2023. on the 20th of October 2023, R3250 paid and the account should have been settled, to my surprised when I call on the 27th October for my statement I was told by Bongiwe and Her manager called Kay that there is R1100 of legal fees that's outstanding but when Bongiwe and I made a payment arrangement on the 26th July, it was based on the total amount owing provided by Bongiwe. now they have *****ulently debited my account R500 after I have clearly told them to stop debiting my account. I regret agreeing with them for a DebiCheck Debit order, now I cannot reverse the debits. As consumers, how can we stop this horrible company from harassing and frustrating us.