What can I do if a "middleman" company is refusing to pass over the refund that was issued for me?

An airline company issued a refund for me for a flight that I did not take. They gave the money to the "middleman" (Cheapoair) - the company I purchased the ticket from originally. for the past 6 months, Cheapoair claims that they are "issuing" the refund and it will take 14 business days to get this refund, yet I have yet to receive the money. I have several emails confirming that they are "issuing the refund," and then nothing happens after that. Every time I call, they apologize and the same story repeats again. What can I do?? The refund is for $720, so it's a big enough amount. Yet, if I try going to a lawyer, I probably will spend more money on a lawyer. I feel so helpless...