Stolen iPhone 6

Hello,

My iPhone was recently stolen.

Today I received the first email that the iPhone is online, next email I received writes that someone has changed some data "Password and Backup email(s)".

After that my iPhone not included in Find My iPhone list. How can I back that iPhone on my iCloud?

On this iPhone I had my most important pictures, there is a possibility to get them back?

Tatjana Bokan