CD4011BE (DUAL INPUT NAND GATE) not working
There are a number of possible problems you could have had here. 

As the 4000 series logic chips are based on FETs, it's rather easy to fry them with static electricity when touching them (antistatic wristbands are nice to have).

Secondly, are you sure you connected to the pins you thought you did? Maybe you had the chip turned around, or maybe you were off by one position.

Or perhaps you even just got immensely unlucky and got a bad chip from the factory. It doesn't happen often, but chip fabs aren't infallible.