I don't know what country your from but here in NZ you can leave home legally at 16.
This however would be a silly idea unless you had somewhere to go.
Call relatives first then try friends try to sort out a long term plan.
Do some research on the internet to find out when you can legally leave.
Call a helpline and ask for advice.
If stuff gets too hard then I would definitly suggest running away, just dont get yourself into a bad situation.
Sleep at a park for a few nights and let your parents ring the police.
This way it will step things up to the next level and you may get th results you desire.
Goodluck anyway. =]