Did you wet-sand the tree-sap or plain dry sanding? I would try Quixx Paint Scratch Remover, it has worked wonders for me in the past. However, seeing as how you've already purchased and tried a scratch repair system I question its efficiency in your particular case.

Worst case scenario, visit a body shop, if your problem is "small" enough for them, they might just hook you up for free/very little cost.

Good luck!