I think it was theirs - obviously the UN doesn't have "UN territory" to partition and give away. Short of giving away antarctic territory or moon territory, there really wasn't any territory that was "UN's" any more than that one.
I should probably point out that:
>I think the world had spoiled the Jewish people when they gave them their own state.
was quite the idiotic thing to say - I fully agree on that.
Certainly, Israel hasn't been an easy thing to build or even keep alive. Still, it was given to the Jews as much as it could ever be given - there was only one location for it, which unfortunately was also the only location for other people. The UN negotiated and voted for an as good compromise as could be made.
Sure, we can define the land as ungivable and therefore say that it wasn't given. With an UN resolution passed giving the jews certain land, and that land still being in their use, I fail to see it as anything more than a random metaphysical question though - on the Politics side of it, there was definitely effort. I think the bad part is the probable background of guilt needed for that effort.