No Refunds

I am a first time user of flysafair website. i purchased the standard flight which includes a 20 kg bag. When going through the payment section i was shown a box for the luggage. At this point i thought i must have misunderstood<br> the lite and the standard options and ticked the box for 20kg of luggage.Unwittingly i had bought an extra 20 kg of luggage. At this point i paid for the flights. Only when i printed did i realise that i had bought 20 extra kilos of luggage!!. On discussion with my wife did we decide that the lite option would be better for our daughters flights.i had made a mistake.<br> i immediately phoned the help line to try to get a refund for the xtra luggage purchased and to try to downgrade to a lite ticket. i was told this was not possible, only vouchers could be issued. This is nonsense. First time user of the website,unclear navigation thereof. An honest mistake .i had phoned immediately and am offered only vouchers.I was NOT cancelling the flight.All i wanted was an adjustment and a refund of the difference. What can i do with luggage vouchers!!<br> This is a contravention of the protection of consumer act.<br>