Topic on Talk:Battlefield 4
This might be a problem on your end then. I think I checked every menu, including the battlepacks screen, and they work fine. Picking up weapon also works for me, just have to hold Y for a bit. Prompts during gameplay are always keyboard icons, yes, but that is already mentioned in the wiki.
Unplug any unused USB devices/dongles, delete the settings files (make sure it isn't restored from the cloud), check if a driver update for the controller is available. Don't know what else it could be.