I keep getting these calls. like 10 a day. Indian guy. sometimes dead air. allways static in the back ground.

they claim to be calling from the "sprint upgrade department". they know my name and what kind of phone I have.

they told me I should renew my contract now because sprint rates are about to skyrocket.

I called his bluff and we got into a shouting match and he said he will put a note on my account that I want "skyrocketed rates"
does anyone know about this number? is it affiliated with sprint? is it a scam?