I ordered some replacement receptacles for all of my 110v outlets (different color). They are type WDR, same as stock but I can't get the wires to punch into the slits. Pushed pretty hard with a screwdriver blade. The replacements are supposed to fit gauge 12 and 14 romex (Wirecon Type WDRDU) and I don't see any for thicker wire. Anyone replaced yours? Is our wiring 10...