Frustrated and Unhappy Customer

I completed the whatsapp change process to move my flights from Lanseria- Durban to Lanseria - Cape town , I was referred between the call centre and online platform but neither allowed me finalise or pay for the change, this is rather frustrating as I was on the line with the call centre only for them to give me options between whatsapp and the app , after spending 2 hours on whatsapp , one minute they confirmed and made the changes the next they are unable to, I require urgent assistance!!!!!!