An export cannot be stopped once it has started, and there is no cancel button for a run in progress.
What happens when it finishes
That depends on your credit balance at the moment the list is ready:
If you have enough credits, the export unlocks automatically and the credits are charged.
If you do not have enough credits, the export finishes but stays locked and nothing is charged. If you buy credits later, you can unlock it manually from your exports list.
I launched the wrong search
If your balance covers it, the export will unlock and charge automatically, so message us in support chat as soon as you can with the name of the export. If your balance does not cover it, the export simply stays locked and costs you nothing.
My export has been running far longer than expected
Large searches take longer than the progress indicator suggests, so give it time first. If a run is genuinely stuck, message us in support chat with the name of the export and we will look at that specific run.