Nightmare Situation need Advice Please!!

[Ghenia Flewellyn]

 I bought a home in March 2016. There were already tenants living in there. The tenants stayed.  They recently moved out within the last 2 weeks. I listed the home for sale. I now have a contract on the home and we are closing in three weeks. Inspection and Appraisal have been done.  I came to the home yesterday to check on it and found that there are squatters in there - a pregnant lady and her 5 kids. They claim to have signed a lease with someone yesterday morning. Someone broke the locks for them and let them in and then change the locks and gave them a key. I made them leave right away. I called a locksmith and changed  the locks. I came back to the house this morning . They are back in the home. They have not moved all of their Furniture in. They tried to  close my  electricity account and change it into their name. I got that email and stopped it right in time early this morning.  I called the police and I'm waiting for them to arrive. Has anyone ever dealt with this situation? I need help right away. I would really appreciate any advice you can provide.