Venezuela never said that it would not accept dollars for petroleum imports, that would be suicide, because the main buyer of Venezuelan oil is the United States, and it is the only one that truly pays for oil. Since the oil that Venezuela sells to Russia and China are sent as payments of debts already spent.
Maduro said he would accept to be paid the oil with other currencies, in addition to the dollar. But nobody will pay Venezuela with other currencies because as I said before, China and Russia are not paying them for oil, and India is reducing its purchases to the Venezuelan market more and more.