The closed guard is considered a dominant position in BJJ. Unfortunately, for most of us as we progress in the art, it devolves into nothing more than holding someone in place. We try the basic attacks we learn, but someone with very little knowledge can shut them down through resistance alone.
I found this annoying, and I'm sure I'm not alone. Holly is going to help me show you a chain of attacks I use from 'closed guard' that may help you solve this. Check it out and maybe it can help you improve your success rate at submitting, or sweeping your opponent on the ground in Brazilian jiu-jitsu.