Empty "feedback" promises

Last year September 2021 I called Std bank to fix my home loan interest rate, they approved my request for only 1 year starting from Oct 21. My monthly repayments went up effective 05 Oct 21 as a result of the increased interest rate as they usually do when changing from flexi to fixed. In December 21 our Governor announced an increase of 25 basis points and since we had fixed ours we didn't expect adjustments to our monthly repayments for a year but there were and we have been trying to get Std bank to sort this out. Instead when we called we were told there were no adjustments made to fix our interest rate, we are still on flexi .No one can explain though how our repayments went up in Oct 21 if there were no adjustments made from flexi to fixed. All they say is that our request was never actioned and there are no records of our Sept conversation. I lodged a complaint internally for them to trace at least why our monthly repayments had gone up in Oct 21 if there were no adjustments made to move us from flexi to fixed and the person by the name of Thobile at complaints promised to call us back weeks ago and so did Cecilia the manager we escalated this to after the complaints dept failed to get back to us within the the period they promised us feedback. We are going to have another debit this month of an incorrect amount since no one is getting back to us. I can't begin to express my disappointment with Std bank as I have always spoken highly of them in my network...joke's on me.