You can’t purchase a second hand DirecTV receiver. When a customer deactivates their account the receiver and all the equipment is supposed to go back to DirecTV so that they can claim it and re add it to their stocks. It is not an owners to give away it is part of the service. Therefore if you have been sold one second hand the status of that receiver is that it is still owned by the other customer so you wouldn’t be able to activate it under your name. You can try to call the company and see if they can transfer the ownership but it isn’t all that likely, you should probably get your money back and give it back to the person you purchased it from and have them return it.