Complain to your airline direct and state that under EU regulation 261 you are entitled to compensation.
Some airlines have forms on their websites. How much you can claim depends on where you were travelling and for how long you were delayed. The maximum is €600 (R9,898).
Remember that to be eligible, your delay must have been within the airline’s control. This includes routine technical faults.
If your claim is rejected, you can refer your case to one of two ombudsman-type schemes — the AviationADR or CEDR (Centre for Effective Dispute Resolution).