Called + no message = blocked

Randy,this# seems to call my cell phone all the time,and then sprint wants me to convert a landline to text message at .25 a piece+they call 4-5 x in a row,i never answer and wont pay .25 to listen to a message from someone i dont know.Whitepages has reports from other people this number calls them too,its a medium threat level as far as spam on whitepages.com