If i allow someone to use my save, and them disallow them to use after they put it in their save, do i have the right to claim the copied part of my save and report the save for so?
Yes, you could change your mind later. But it also depends on exactly how copied it is. If they took it and made significant changes, and then gave credit, I'd probably leave it up. But if it's taken with no changes and uncredited, I'd take it down.
Another thing to note is that you should take reasonable efforts to notify the author of the save containing copied portions that you have retracted the usage of the save.
For example - messaging or commenting on their save is reasonable. Simply updating your save description or only commenting on your own save without notifying said author of the save that contains the copied portion is not reasonable. eg. changing your mind but not telling anyone wouldn't be seen as reasonable and thus we would give the copying author more leeway.