The kno tlook like you made it yourself by not starting a the bottom and working you way up.
But start by getting slicone spray from a hardware/automotive store.
Spray the crap out of the knot and start toi finger comb the thing breaking it into larger section and then work those sections. You will probably need 8 hours to so this and A LOT of patients. Do rush it, and go slowly.
Once the are is knot free then you reset the kinks with hot water. Never try to straighten a wig this is still tangled or knot as this makes the issue worse.
If it still looks like a frizzy mess then you only spent a day on this.