Accidentally didn't trust a certificate..HELP

Someone please help. My efforts to resolve this have been futile. I accidentally clicked "do not trust" on a certificate because I didn't know what that meant. Now, I can't use the wifi at work. How do I undo that? I have reset my network settings, reset all settings, tried to forget the network several times. There has to be a way to resolve this. I feel like I can't be the only person out there that isn't tech savvy and had never heard of a "trust certificate." I've reached out to the Apple Support team multiple times and they are at a loss. Apple is really dropping the ball on this one.