It stinks to lose deposit money when trying to purchase a home. It sounds from your description like you knew prior to the commitment date that there might be a delay in being able to deliver on your obligation to provide a commitment from your lender. So this could have been handled pro-actively by your agent prior to the actual commitment date deadline.
The change in Connecticut Real Estate Law about 10 years ago which established Buyer's Agency was designed to prevent just this type of problem from happening. I hope you have a signed representation contract with the agent (technically with the entire real estate company) to work in your best interests.
Given the situation you have outlined, you are fortunate to have settled for half of the deposit from the seller. If I were you, my next step would be to ask the agent, in writing, to refund the balance which you lost. The next step would be to send a written request to the manager of the real estate office or the owner of the company. If they are not helpful, I would make a written complaint to the Department of Consumer Protection which licenses Real Estate agents and brokers. If this state agency agrees that your complaint has merit, they will require the real estate company to respond to your complaint in an effort to resolve this problem.