R2000 cash Parking fine

My son (minor) was traveling alone to Dbn on the 19/06. I dropped him off at the airport at 5am the Flight attendant called me to tell me that my son luggage is over weight and if i don't make payment he will miss his flight. I turned around and rush back to pay. I parked my car at the drop off zone as it was the quickest way to get to payment point. I wasn't even gone 5 mins because it was early in the morning and the airport was not busy. When i got to my vehicle they were clamping my vehicle. I explain to the security guard my emergency but did not budge. They then sent me to parking/security office where i sat there for 3hrs they kept telling me they calling the Manger. After waiting 3 hrs the manger tells the cashier to tell me to paid R2000 in order for my car to be released and that i should pay R2000 in cash. I eventually paid the R2000 in cash in order to get my car unclapped.