Hi kuum0,
Thank you for posting in the Apple Support Communities. From my understanding, it sounds like you’re having trouble deleting the iOS update. I’d love to help.
Be sure that you’re looking in iPhone Storage settings, rather than iCloud settings. The steps to take are found in the section, “Remove and download the iOS update again” here: Get help with over-the-air iOS updates
If you’re still unable to update over Wi-Fi, try updating using iTunes. Before doing so, be sure your device is fully backed up to iTunes or iCloud. When you’re ready, here are the steps to take: Update your iPhone, iPad, or iPod touch
I hope this helps get you started. Kind regards.