Unfair charges to students and inefficiency by the postgraduate administration officers

I did my PhD program for 2 years at the University of Pretoria, and in my third year, I was only for examination results. However, the University charged me the tuition fees for the whole year. I made several equiries with no luck. There is an administration officer called Kenneth Nkanyana who on several occasions failed to respond to his emails. They used graduation ceremonies as an excuse for delaying giving me my confirmation letter. Is it appropriate for the university to cause inconveniences to our lives because other students were graduating? Besides, it takes less than two minutes to prepare a confirmation letter since the template is available.