Walls and Ceilings - Help, outlet holes cut too large!!

In a bind!! Had a guy add a small room onto an existing one. He cut most of the holes for the switches and outlets when putting up the drywall too big. Unfortunately I didn't notice until I was all done painting and tried to put the face plates on. Some are an inch too big!! Some of plates are for three switches so that makes for a long mistake. This guy must have been a flake because he left town and now I'm stuck with a problem. Being woman, I've not had to deal with this particular problem. I've patched small holes with spackle but nothing like this. PLEASE help me out with a solution other than replacing the drywall and all my painting!! :confused:

What I would recommend is to take the face plates off, get some Mesh Tape and apply it over the cut out where there should be drywall. Take some joint compound and apply it, let it dry, sand it smooth and re-paint area..

They make oversized outlet covers - I don't know if they are big enough for your situation. Otherwise do as instructed above.