There's no way to get rid of link transfers if you're using the free service. Once you complete an upload, you'll have to wait until the transfer expires. That means the regular 7 days apply. Please check that you are sharing the download link with the right people before doing so.
If you're a Plus user, make sure you log in before starting an upload. That way, you can always look up a transfer in your transfer overview. Here's how to get rid of transfers from your Plus panel: