Does anyone live with someone they detest?

I hate my roommate...he racked up a $700 phone bill (on my acct.), he steals my food and is a general leech and ingrate. he is a big selfish spoiled brat. He has mental issues but it doesn't excuse his behavior.His parents are paying for the phone bill but i was on the phone with verizon for an hour today and several times before trying to straighten out this mess. we signed a lease for a year. any advice on dealing with this?