If your offer was accepted, then you should have immediately moved into an attorney modification or review period. So if the seller's agent was not responding to you, then you could have also had your attorney contact the seller's attorney.
Either way if you've made a request of the listing (seller's) agent that is not answered within 3 days, then you can potentially go directly to the seller themselves with the same request.
I'd put the listing agent's boss (managing broker) on record of their failure to respond, but you could start ignoring the seller's agent and either deal directly with their seller or with the agent's managing broker.
Broker Associate, Keller Williams Realty Chicago Consulting Group
716 E. 47th St. Chicago, IL 60653
(773) 770-5947 (cell) (312) 577-0985 (fax)
Ciao for now -