You would have done well to at least look it up in something before getting smug.
Here is the Wikipedia reference, that is pretty mainstream.
https://en.wikipedia.org/wiki/Timeline_of_the_name_Palestine
Summary:
Earliest known Egyptian reference: 1150BC. the word is "Paleset", attributed to a people of a neighboring region.
Earliest Assyrian reference: 800BC, "Palashtu", attributed to the same people and region.
The Biblical "Philistines" are often (rightly and wrongly) associated with the same people, but "Philistines" is used freely in the Bible as a reference to people of other nations dwelling in the holy land.
Earliest Greek reference: "Palestine" 5th Century BC, in writings of Herodotus.
Romans renamed the region of the Jews "Palestina" after crushing the Jewish uprising of 2nd Century AD.
So lets not forget that God has brought both judgement and mercy on all people (including the Hebrews) throughout the ages, and none of it is cemented in stone.
Lets not pretend that the New Testament has not happened.
The Romans also invented the name "Christian", (Acts 11:26) probably to mock the followers of Jesus, and as we can see names stick.
Palestinians who opposed the British mandate preferred to associate themselves with the Turkish Government.
You build a weak argument against the existence of Palestine based on their protests of those who lost the war that promised independence.
I am sure that you know that the mandate was also fought for by Palestinians, alongside poor Australian diggers.
The fact that people in your religious camp teach each other not to acknowledge the name of these people in a testimony to much darkness in your soul.
The fact is that very serious crimes have been committed by Israeli terrorists against Palestinians, and by doing this you cover for the crimes, thereby incriminating yourself also.
So what line of defense would you be setting up against this allegation?
"How can there be massacres, rapes and torturing of tooth fairies when tooth fairies do not exist?"