In my experience you can't tell the voice or voices to stop anything that they don't want to, I wish mine would stop doing a lot of things but he won't so the best I can do is ignore him and never speak to him again.
I've been ignoring mine for two and a half years so far and he hates it so that gives me a little happiness, he'd like nothing more than to be spoken to but I just refuse to until he starts behaving himself.
I am on medication for my voices, so I couldn't really help you. Although if wish to so desire to stop your voices telling you that you don't have friends, I would highly recommend this; play music through headphones, from a personal cd player, and or mp3, set up, and that you will give you the chance for the voices to diminish off, and stay away for a long time.
Also, I highly advise for you to see a doctor, or pshychartry doctor, for medication, to surpress your voices down, and kept down.