Felt like a hostage at the airport

On Monday 7 Feb 2022: My dad arrived at about 21H00 at domestic arrivals. I do not fly often and rely on the direction as per the overhead boards. I've entered a parkade with multiple signs on the road side but non indicating long term parking (pictures available). I've managed to fetch my dad and were at a pay station in about 25 minutes. The pay station registered an amount of R480 which I found absurd. The parking manager station explained that it was a long term parking, Well knowing that this was a clear mistake the airport did not seem to have an authorities customer agent available to assist. And stated that I can only leave the airport if I pay at least half of the R480. That was a lot of money to me and when paying the R240 the machine "cheated" me wit a further R20. This experience decreased my esteem of the International Airport (Oliver Tambo) significantly.