You applied too much heat to the pads and they became detached from the underlying substrate (most likely fiberglass, not plastic).
I would use much less heat in the future and work at a quicker pace.
To fix, find the traces that would have gone to those pads. Scrape away some of the soldermask on these traces so you can solder to them.
Since the board is damaged, it's probably a good time to get creative to fix it. It looks to me like the traces are very near the damaged pads. I'd scrape some of the soldermask off and orient the capacitor such that it touches both newly-scraped trace. Then solder on a blob at each end .
Here's what I mean:
Scrape the dark green area to expose copper.
Position the cap (if you are committed to using the original part - you can also replace with a leaded through-hole component and bend the leads to fit) so it will make a connection between the two.
Also, it looks like the top trace continued where the lime-green box is, and is now broken. You will want to scrape away the solder mask there as well, and bridge the two traces.
Take this with a grain of salt, as I do not know your design or board layout and I'm just making guesses how to repair this exact board. I'm just offering techniques on how to remedy this in general.