u/Anion078

I bought a Kyocera 902kc from zenmarket and both the title and the description of the product crearly said that it was SIM-free and unlock but once it came to me when i try to put a O2 sim card it first asks for the pin and works fine but then for getting network data it asks me for "SIM Network unlock PIN". I can start the phone without putting it, then it will say Invalid Usim and in the moment i try to put an APN it deletes itself. Is it locked? It was from SoftBank