I installed Windows 10 on my Mac using Boot Camp Assistant, but later decided to remove the partition as I no longer needed Windows. I did (or tried to) using Boot Camp "restore", but it gave me an error saying it failed. Now when I go into Disk Utility, the Windows partition doesn't appear, so I can't delete it. But it's there somewhere because I'm only showing 180 GB on the Mac partition (not the full 250 GB).
Going back into Boot Camp Assistant doesn't help, it just allows an option to make another partition (no delete or restore option).
I'm at a loss for how to proceed.