SARS, thorough and complete

This time we're lucky. We had paid (Inland revenue - South African Revenue Services) but they sent us a note anyway. Well a three page report for, R0.01 (a full bill for 1c?). We'd paid the amount as usual, but they had overlooked it (as the UIF contribution). We've written for their forgiveness, and pray for their forgiveness. I honestly thought that 5c (R0.05) was made the minimum tender. What was the story?