[Motor31]

Is it the little spring tab that holds the little "top hat" round fittings into the depression on the side of the fridge? If so then a spring clothes pin will substitute until you can get a replacement through a parts house. If it's the top hat itself I have no idea other than maybe a wooden plug carved to fit.

If it is the retention bar, just use a spring curtain rod from wallyworld. We use them in addition to the little retention barrier built ito the shelf.