I dont use travel agents
try for cheap flight to bangkok (internet)
then try this link for bangkok to phuket fare
http://www.bangkokair.com/
then for accomadation
http://www.phuket-info.com/hotels.htm
or try airfare to aus-singapore-phuket
or aus-kl-phuket but airasia is connection and not sure if flying to phuket yet
http://www.airasia.com/general.php?p=pmain&l=en
hopes this helps