My first step would be to discuss this with your real estate agent. He/she can hopefully explain the delay and/or talk to the seller's agent for an update to find out why escrow hasn't closed. He/she should also ask you this question: Do you still want to buy the property?
If your answer is yes, he/she should draft an extension of time addendum. If your answer is no, he/she should draft a cancellation of contract, release of deposit and joint escrow instructions.
The next step if the above scenario doesn't work out is to contact your real estate agent's broker. If he/she IS the broker, proceed to step 3.
Step 3 is to contact an attorney and let the real estate agent/broker know that you have done so. Depending upon your purchase agreement, you may have agreed to arbitration if a dispute arises. Now it's time for the attorneys to take over...your attorney, your agent/broker's attorney, the seller's attorney and the seller's agent/broker's attorney.
P.S. Here's a link if you need to look up an agent/broker - http://www2.dre.ca.gov/publicasp/pplinfo.asp