Look, unless you can find out where they are located, what their address & company rego is, you're not seeing your money.

They essentially have complete control over the private keys and as you said, it's up to them to sweep the funds out of the ETC wallet.

They have absolutely no incentive to do so. They don't have a brand reputation to begin with so they don't have anything to lose, and they know that you don't have any other avenues of contacting them unless you somehow magically track them down IRL (which is pretty much impossible since people have been trying to do it for years now).

Just expect the worst and hope for the best. All you can do.