Where can I buy push type clips for fog lights?
 

I needed to replace the bulbs in my fog lights of my S40 2002. But...apparently the knob which holds the bulb which you twist counter-clockwise to remove can be put the other way around and gets stuck, which I think is an egregious design flaw. This prompted me to remove the whole assembly from the front bumper. In doing so, it's held by a clip-in screw of sort that is made of plastic. And I broke it.

You can see the assembly here https://imgur.com/bmcEs8e, it's a clip-in screw that goes into that top part, on the top edge of the image that I've circled in red. It goes through the underside of the front bumper and inside of the assembly to hold it in place.

The reason I broke them is also because they are made of plastic, yes plastic screws and I basically damaged the head because it didn't turn.

Where can I buy replacements? Or perhaps anything else I can use as a replacement.

I'd recommend going to your local auto parts store, and peruse their "miscellaneous hardware" section. There's almost always something there that will work. Or you could stop by your friendly Volvo parts department and see if they can give you any guidance.