billing and service is horrible

I set my spending limit to 250 for the past 6 months but my bills is always higer than the spending limit I set I spoke to an agent from Telkom and everytime I call the system is down. I was finaly assisted by a manager whom doesn't know what hes talking about and says he cant see the spend limit I set. the service is terrible and im paying for things I did not set on my spending limit