Lawyer up... potentially sue the LLC. Anything else probably puts you in a worse situation.

As I already wrote, there are probably 2 ways to look at a mining contract:
1) You're paying money and getting money back (progagbly Giga's lawyer's pov) - this means you're earning interest on an investment etc.
2) You're paying money and getting a service back (hashing work converted to Bitcoin) - similar to any contract that sells computation power (like render farms).

Probably nobody knows which of these 2 will hold in front of a court (even the "you're paying money" is debatable, if Bitocin are not money in the first place), the worse case of these 2 is of course case 1), where Giga nearly operates a bank/money printing operation from a legal pov. To decide definitively you need to lawyer up, drag Giga's LLC to court and you'll probably settle this out of court, since it's much cheaper to just pay you whatever you want to have for the 40 shares than to risk having to pay all "bond"holders if the court really makes a decision.

There will be a LOT of people not jumping through these regulations and just writing the few shares off, so Giga can probably easily pay his lawyer from the money you threw at him.