Can seller back out of contract just a day before closing

[Shailesh Patil]

I am buying my first house in california. Everything was going very smoothly from both parties until on the day of funding I got call from my realtor stating, seller puts hold on transaction saying that they didn't know they had to pay commission to realtors. My realtor issued 1st performance notice to COE or money damages and they havent responded anything yet. The problem is with seller and their realtor about the commission. For some reason, seller is just trying to not sale the home anymore i guess. In the contract there was NO contingency from either side and we provided 40 days for COE and 10 days after that for rent free living to find home and they havent done so till COE so might be the reason they want to cancel. What are my options to go after a property and not money. I will be homeless in a week as I have given move out notice to my landlord anyways for vacating the renting apartment. Ordered new appliances and have done extra shopping for home decor worth 2k or so. As per seller agent they offered to lower commission on their part but seller is not agreeing to anything anymore.

What is the importance of signed listing agreement in this case if we go legal? Not sure whats signed between seller and seller's agent.

I have deposited all downpayment + EMD + appraisal gap already in escrow and secured mortgage and done signing in front of notary as well. 

What are my chances to go in legal and have seller complete the sale anyways.