BFL isn't/wasn't a ponzi and has nothing to do with BT, not sure why you make that comparison.
When BFL first opened up their Monarch refunds, the reason that they publicly gave for why there was a sixty-day delay on refunds is because they had to sell your place in line to another customer. Using a later customer's money to fund the payout of an earlier customer is practically the definition of a Ponzi scheme. That's why I made the comparison.