Wall plug gives way. How to replace?

[Bricco]

1. Installed window sills with allplugg but they are starting to give way and have caused the sill to hang 3-4mm which looks shabby. Does anyone have a tip on how to remove the stuff without damaging the drywall and wallpaper so I can install better plugs?

2. What is the most suitable type of plug to use for fixing the flower sill mounts? The mount itself is between 20-50mm deep where the screw should go in.

These are what I have today. Not recommended.

 

[magnu]

Take a chisel and cut off the neck. Then press the plyggen into the wall.

Try with metal expansion plugs, available in many places. Choose the expansion plug size according to the load. I usually opt for 12mm for heavy loads. Moreover, these come in two variants for single and double boards.

 

[Bricco]

Take a chisel and cut off the neck. Then push the plug into the wall. Try with metal expansion plugs, available in many places. Choose expansion plug size according to the load. I usually go with 12mm for heavy loads. These also come in two variants for single and double boards.

I've thought the same and usually do so, but the wall is filled with some kind of foam that feels like polystyrene, so I can't push it in and probably can't remove it either

 

[Hubbe2]

Just bang it and the foam will probably move. Set it up with metal expanders; plastic plugs are crap. Always avoid things named universal* or All*, it just means that it's not particularly good or bad anywhere...