The UN only created the Gaza Strip, Israel and the West Bank. They did not create any place called Palestine, because the Southern Syrians already had Jordan as a state.
Of course the UN didn't "create" Palestine, because the term had already been in existence and used in reference to the general region before the UN even existed:
(Now granted, the Arabs who agreed to revolt against the Ottomans were somewhat incensed by this territorial division amongst the European powers, given that this all appeared to go against the terms of the Damascus Protocol, as well as the diplomatic correspondence between the British High Commissioner to Egypt and the Emir of Mecca. Likewise in regards to the Hogarth message of 1918, which did not become publicly known until over 20 years later, as noted from page 24 of the 1947 UN Committee on Palestine's report to the General Assembly: "The Mandate speaks in general terms only of safeguarding or not prejudicing the "civil and religious rights" and the "rights and position" of the Arab community in Palestine. Regarding interpretation, in January 1918 the British Government assured King Hussein in the "Hogarth Message", that the aspirations of the Jews for a return to Palestine would be realized "in so far as is compatible with the freedom of the existing population, both economic and political." This interpretation, however, was not officially made known to the Permanent Mandates Commission until 1939 nor was it acceptable to the Commission as a whole.")
(We are still dealing with the consequences of the post-war division of the Ottoman Empire.)