Help! Help! Oil Company not paying us! What can we do?

Hi All, I am new to this group but hope someone can help.

My family and I own together mineral rights on about 7,000 acres throughout Fresno and King County, California. When oil prices dropped below $50 a barrel a few years ago, virtually all the drillers/operators stopped paying us and some signed back their leases to us. We recently found out that at least one of the operator's was pumping oil on one of our wells all this time and selling the oil to a large oil company and not paying us our share. When we found out who he was selling the oil to we contacted them and they contacted the operator for us and, at this time, he agreed to let the larger oil company pay us our part directly on any future proceeds.

My question is this. Is there anything we can do now to get paid for all the years he has been pumping oil and selling it and not paying us? I believe it was 2013 when he stopped paying us. He is very hard to contact and has never returned any calls. Several family members are very upset and want us all to hire an attorney together. Does anyone know what recourse we have (if any), or can anyone recommend an attorney familiar with mineral rights issues that could possibly help us? Is there any government agency in California that could help us, or are we on our own?

Really appreciate any help with this matter. Thank you very much for your time. Vern

What is the name of the operator? Contact Jean Pledger on this site. She is an attorney who is an expert on oil leases in California.