The smile helps. If it fails, say something like, 'I can see you are very upset, Sir/Madam, perhaps you'd like to fill out one of our feedback forms? The Authority take customer feedback very seriously, you know.'
In no circumstances must completed feedback forms be inserted into the Suggestions Box. They can be disposed of as sensitive waste in the usual way, by burning or flushing.
If the situation escalates, and develops into General Borrower Unrest, Revolt, or Anarchy (particularly during half term or Saturday mornings) please refer to: Terrorist Threat and apply the instructions found therein accordingly.