Unexplained bond increase and Customer be ignored

Our bond repayment changed in July we were not notified or aware of any increases, we called the home loans and was advised they are not sure and will investigate, we went into liberty promenade branch on 10 August 2024 to seek assistance and advised we must call home loans, same response was not sure but will advise, we spoke to the consultants and they tried calling the home loans department on teams and no one answered their calls, we was told by the team leader that she will contact the home loans manager and agent that assisted the first time to assist us. Monday the 13 August she advised she spoke with Zanele the home loans operation manager and Lebogang the agent and according to their explanation it was an insurance that was only activated after 18months and some problem they picked up on their side and they will call us to explain, no communication was send to us about a problem or outstanding insurance just a sudden change on our bond repayments , if the bank can change and take as they feel who's money is the account , if they made a mistake and want to rectify , you speak to the customer not take as you feel fit to fix your error, only on the 21 August received a call from Lebogang and when expressing my discuss at the fact that they changed my bond repayments collected amounts not agreed upon and the fact that they never communicated anything to us , she said she will speak to her manager and get back to me it is the 29 August 2024 and no communication again, they deducted what they felt , could not explain what happened , blamed a error that they know realized was there after a year and a half and I have to be happy with this treatment. FNB standard of customer service suck, and since when can funds be taken without the account holders consent. FNB must explain how they increase and add monies without a customer consent or allow their staff to ignore customers