If it’s ABS (which most thugs are) try methyl ethyl ketone to melt it back together.

Just a dab of MEK will melt the plastic, but it evaporates/dissolves quickly. Once you apply it press the pies together firmly for a few minutes, then let it cure for a while after that. The bond should be as strong as it was from the factor. Then if you want apply some JB weld for extra strength.