Kulula you should be ashamed

My elderly parents (father 85 and mother 78) travelled with Kulula from Johannesburg OR Tambo to Cape Town on Sunday 3 June 2018.

They both have difficulty with movement and I therefore pre-booked specific seats with extra leg space at an emergency exit on either side of the aisle for them. The booking of these seats was at an extra cost.

When I enquired from them after their arrival in Cape Town whether they were satisfied with the seats and extra leg space on the plane, they told me that they were seated in a regular row next to the window and in the middle seat. Eventually the third passenger in this row moved to the seat next to the window and my mother could sit next to the aisle. This means that they sat cramped during the whole flight which is what we specifically wanted to prevent / avoid by pre-booking the seats next to the emergency exit.

When I heard this I was very upset and it made me extremely angry. What is the purpose of booking and paying extra costs for specific seats and the passengers are not seated in them? I also request Kulula to refund my parents for the additional costs of the specified pre-booked seats.