I might reach out to a few others in the future. Note that I'm not out to sue HF, merely to get a full refund in BTC as I am a day 1 customer covered by the original ToS. If I find an attorney that specializes in consumer litigation that is willing to take this case the most likely way forward is that they will draft a Letter of Demand. That would put the ball back in HashFast's court.
You don't need a consumer protection lawyer, you just need a contract lawyer. It's a pretty simple issue... no party to a contract can change the terms unilaterally like they're trying to do.