I will suggest you handle the matter MATURELY....Call this girl up.....talk really gentle....ask to meet with her in some place maybe, CHEAP RESTAURANT....
(Make sure you GADGE OH). Get talking...tell her about the phone and your PROOF that the phone she is with is yours
(MAKE SURE YOUR PROOF TANGIBLE OH).....Then tell her your mind....infact run her down with belittling words but no SHOUTING, be cool dude..BE COOL!.....but on an actual fact, you are transferring your message across...When you are done...walk away in style....enter your car or climb OKADA
"in style"....She will feel really bad i bet you.....except the girl no get
CONSCIENCE...Taking the phone back drops your SWAG...fashy!..GOD WILL PROVIDE another.....