OP as far as I know a gift is something given without expectation of quid pro quo---so by what theory do your parents expect return of a completed gift apparently made under CA law .
There might be some issues of return of dowry under religious law but that's not applicable and you may be unwelcome child in parents home hereafter but that's not relevant either to CA law.
You keep twisting and turning but so far you haven't made a solid legal point about his duty to return of the gift made by others to either you or the maker ---why--because there are none to make!
If you can barter or jawbone a resolution--so be it, but I suspect you closed the door on those possibilities some time ago--your tone suggests same.
There might be some issues of return of dowry under religious law but that's not applicable and you may be unwelcome child in parents home hereafter but that's not relevant either to CA law.
You keep twisting and turning but so far you haven't made a solid legal point about his duty to return of the gift made by others to either you or the maker ---why--because there are none to make!
If you can barter or jawbone a resolution--so be it, but I suspect you closed the door on those possibilities some time ago--your tone suggests same.