Depends on the contract potentially. It's why most larger business arrangements that could even possibly include such a refund (as part of the contract), will have specifications covering that. I'm curious what was in their agreement, if anything. For example, if it had a clause that allows for returning the dollar invested sum.

A court will usually find against you if you repay in a debased currency or similar however. If I tried to repay a loan, with no contract, in Venezuelan bolivars based on their former value on the date of the origination of the loan five years ago, that wouldn't get anywhere in a court of law, you'd lose easily.

All indications are that they're going to view these as securities.