My iphone was removed from Find my iphone and now I cant get it out of lost mode

Hi! So, I have an iPhone 4s. A 'friend' of mine stole it from my house, so naturally, I put it on lost mode. She then removed Find My iPhone from the phone and now I can't get it out of lost mode, as it's no longer connected to find my iphone. Are there any ideas as to what I could do? I would like to avoid completely erasing everything because I dont know if my pictures are still on it. Thanks for any help.