Have you contacted T-Mobile? If the police are involved they can get them easily. If its just you, then either contact T-mobile or you can check your account online...T-Mobile is good about showing a listing of all calls. You can print it that way. Good luck!
Short of a court order, it's usually not possible to get those. Most companies keep them for seven years, and if it's a legal issue then it may be possible, but getting them printed is a far-from-routine matter.