Pre-booked seat changed

<p>In February I booked 2 return tickets from OR Tambo to Cape Town for our Decemebr holiday. I selected seats with extra legroom and paid the R48 surcharge per seat. This was reflected on the email confirmation I received. I was disappointed to note on the reminder that I received 4 days before my flight that on my one trip the seat had been changed to an ordinary seat. I phoned Kulula to enquire about this. Luckily there were some seats available in the emergency exit row available. I am wondering why this happenbed and what would Kulula have done if there were no other suitable seats availble? There was no indication on the confirmation that I could expect a refund for the surcharge.</p>