Shitty Roommates

My best friend and I are in the middle of a damn feud with shitty roommates who refuse to leave and refuse to pay their fair share of rent. Our mistake was letting them pay less in the beginning of the lease, after they said that in February they would be able to pay more. Things have not gotten too bad, by that I mean there hasn't been any spiteful destruction of property and what not. They just do not speak to us at all.

Anyways I was just wondering if any of you here on the O-Deck have had some bad stories about awful roommates and what you have done about it?