Bad service

I am not happy with Standard banks current service I enquired about putting a lump sum on my home loan account so that my instalment be taken off that amount and was told that I can and that I need to first transfer then send a letter for my request .I did exactly that and now standard bank are doing their own request of thier own. First they recalculated the instalment that is not what I wanted. Now they send us a debt restructuring form that is not what we requested what must we do for standard bank to take us seriously we are not happy at all with standard bank there is a reason why we requesting this and they messing about our lives. Been sent up and down over a strait forward request honestly is tiring.