ouch.
I would do that now. That aside, you should still be able to prove that you wrote the songs, paid for recoding studios etc. Do you have the masters? there is usually a paper trail. If they have no contract then they likely have no evidence of a claim. As I said, start by requesting a take down notice with google citing any and all pages related to the work, also to Facebook. I would also re-do the take down on YouTube, describe the case fully. Not that you have misplaced the contract.
What country are you in?