Dodgy cabinet fitter!

Recently, a double wall unit in our kitchen slumped down on one side, dropping some glasses and plates on the floor. We emptied the unit and took it down, to find that the guy who fitted it had drilled straight through a 45mm cavity, into the brick work. I can't any evidence of rawl plugs used. I am guessing that because of the cavity and the weight of the unit, the screws were just slowly pulled out of the wall. The plasterboard has also caved in down to the next timber, about 250mm lower than the brackets.
I've had to cut away the plasterboard, and I think the best thing to do would be to put a new stud in place, and then a sheet of plasterboard or mdf to cover the gap, then fit the cabinet fixings into the stud.
Does this sound like the right course of action? I'm guessing that the hollow wall plugs wouldn't be suitable for the kind of weight a double wall unit will subject them to.
Any help with would be amazing, I've not done anything like this myself before

Greg Lebowski said:

I've had to cut away the plasterboard, and I think the best thing to do would be to put a new stud in place, and then a sheet of plasterboard or mdf to cover the gap, then fit the cabinet fixings into the stud.
Does this sound like the right course of action?

Click to expand...

You're dead right - just make sure you get a real good fixing through the stud into the wall