Cell phone warranty ?

I bought a motorola defy (t-mobile) from Craig list. As soon I got home than realized phone is not working(two weeks old). I went to t-mobile but they can't help me without a receipt. Then I called motorola for manufacture warranty and they told me to send this mobile to motorola repair center with receipt. Since it's udder warranty, are they(motorola) going to fix my phone without a recipt? (I didn't send this phone yet).