The reason it failed was the plasterboard fixing was totally unsuitable for that situation. You need to drill thru to blockwork [I can see it thru the hole] and use plugs and extra long screws, a spacer of copper tube in the plaster will stop it crushing the plaster when you fix brackets.Or you can cut out the plasterboard in a narrow strip the width of the unit and replace with a piece of timber to act as a spacer.
