Seeking help identifying the United Oil & Shale royalty payment company

Greetings. United Oil & Shale - New Operator is the operator of many wells in Texas and Oklahoma. It appears that they are not the agency issuing the royalty payments. They have one telephone number in Woodford, OK that is never answered. Does anyone know which company is responsible for the royalty payments? Is there a better telephone number for United? Thanks for your help!