1) i plugged in my headphones (increased Volume to max) it showed increasing volume and i can hear sound i unplug the headphones, no volume.
2) Plug headphones, turn on Bluetooth, off for Wi-Fi, increase volume with headphones plugged in
3) remove headphones and keep pressing the up volume few times, than adjust the volume on setting to low and with the up button on side of phone increase it you will notice the volume is going up but no sound.
play a movie or something and increase the volume. It worked for me.
I did not learn from my mistake and thought 6.0.2 will definitely have fixed this issue (i had too much optimism in Apple)
speakers stopped working.
I did what any desperate person does, and no i am not paying 200 for a refurb so i can go through the same issue again, I did the one that apple deleted and said not to do, then i plugged in the headphones, increased volume, removed headphones and increased the volume and voilà it worked like a charm.
hope this helps you guys.