Poor trained call centre Staff

I called the Absa call centre home loans division with regards to a query on my home loan.The person who took my call was clueless in explaining the answer to my query. Why do large banks like Absa employ staff that donot have the necessary skills and expertise to handle queries regarding bond calculations and payment calculations. How PATHETIC!!!!! This person could not tell me why my repayment went up by 2,86% when the most recent interest rates increase was 0.25%. This is not the fault of this particular staff member , the management of Absa are to blame because it seems they fail to train their people properly to handle complex queries.REALLY FRUSTRATING FOR US CUSTOMERS WHO HAVE TO DEAL WITH THIS INCOMPETENCE!!!