Kaching parking app charged incorrectly

I didn’t know Netcare doctors parking Sturdee Rd Rosebank is a Kaching client. The boom certainly didn’t open automatically. I took a card when I arrived and paid for parking. When I left I struggled to have the boom gate open using the paid card and had to call for assistance. Kaching charged R6 parking and has not rep**** to my emails for a refund.