Well, the main factor in ensuring the terms set for renting out a property are met is the Lease agreement. From what you have written above, I believe you do not get into a written agreement, you just had a verbal agreement of some sort. You see written agreement is very important for these kind of matters as a written agreement would have written dates and terms for payment of rent and other utilities and you could have complained to the police easily on basis of these terms and conditions. However, since it is your property you can still complain against the tenant in the police. This would be followed by a court case through which you can evict the tenants out of your house.
Every state has different laws regarding landlord tenant issues. I manage properties in New Hampshire, therefore, if you are in NH as well, feel free to respond and I can help you with your problem.