Will the earnest money ever get released?

So we were involved in a real estate transaction where we cancelled the contract during the attorney review period. For whatever reason (bitterness?), Seller's listing agent doesn't refund earnest money. The home sells within the week for larger amount than our contract. So I surely don't see any possible claim that Seller was damaged...even if we/Buyer was wrong in handling the contract.

Question: Ethically, can listing real estate agent ever release the money w/o written approval by both parties? We're considering using the Chicago Board of Realtors arbitration system...not enough money to sue but just a funny question...will the money just sit in the real estate brokerages account forever?