Shop question - damage What would you do?

[Mal]

Ok in another thread I describe my traumatic trans rebuild. Related/unrelated issue.

While my car was at the shop waiting for me to get a trans from IN the back of my soft top was torn/broken in. Wait - it was already messed up and the prev owner had a decent patch job done on it.

They claimed it was hail. The back window was broken through.

Now heres the clencher. Whaatever crud the prev owner used to patch it came loose and after two weeks of sitting, after the hail that broke it, the crud melted onto my back deck making a three by five inch black stain/goo on it.

What woud you do?

Pic of my car: