Baggage not included in flight tickets

I booked flights through Helene Kotze to Australia and New Zealand through Flight Centre, the flight dates being 1 August 2015 from JHB to Sydney, returning to SA on 18 September 2015.<br> <br> .In a letter from Flight Centre (Claire Basley), .the following flights were stated as Premium Economy: Jhb to Sydney, Sydney to Brisbane, Brisbane to Sydney and Sydney to JHB. The last three flights on the list were Economy class and not Premium as stated on the travel documents.<br> <br> In a letter from Claire Basley (Customer Care Consultant for Flight Centre) she mentions that on some low cost regional carriers, the baggage allowances do not always apply. This information was not mentioned during the booking process.<br> <br> I had to pay Aus$ 320 for baggage on the flight from Brisbane to Wellington as the ticket supposedly did not cover baggage for this part of the trip.<br> <br> I tried to claim Aus$ 320 from Flight Centre, but they have offered me R 490 in a letter from Helene Kotze. This amount I refuse to accept<br> <br> Your help please!