Horrible customer treatment

I have had a car on rent to buy since 2019. In 2021 i changed a job and pay date changed. I then requested change of debit order date in August 2021. No response and made several follow ups with no response and was kept being penalized 100 for retuned debit order. I have been also charged 14 infringement redirection fees which now are reduced to 9 and only 5 appear on the ARTO system which i sent several emails to query without success. Ultimately they acknowledged their mistake in delaying to change debit order and made an arrangement for me to pay the outstanding fee in 4 months which i agreed now all of a sudden a rude financial controller by the name of Heidi send people to collect the car and send me rude emails l accusing me of giving falsified information and my credibility of character. I sent her proof but still threatened me to come collect the car. I asked her if i was supposed to just pay even though im not satisfied. I have always been communicating with Banji and Brumilda and have clear background on my case but now she disputes her decision with no clear knowledge of the matter.