Main site storage space maxed out no matter what I set it to

I am unable to upload any more images to the media library of my main site, because I’m out of space. But I’ve gone repeatedly to Network Settings and played with the upload limit for the site. Currently it’s set to 10,000 MB. I’m still getting a message that my upload max is the network default of 50 MB. This is a new issue, but I’m not sure what’s causing it.