POOR SERVICE

i was at the Guatrain station in Pretoria this morning. Loaded my Gautrain card and paid cash at the self help kiosk. Th machine gave me incorrect change. i went to the cashier explained my situation, asked me for the slip which i went back to fetch. After producing this i am told my slip is incorrect, I explain this is the only slip I got and was told the machine must be checked, i left my details as i was rushing for work. I was treated as someone who is not telling he truth and was told it would only take a few minutes but i am still waiting. this incident happened before 6 this morning. i truly feel the cashier could have been more understanding and showed me a little more courtesy.