Calls From Sprint Phones

My straight talk phone cannot receive calls from Sprint phones, or at least one of a friends and from sprint customer service.   The calls go straight to a message...Verizon Wireless, the number you dialed is disconnected or no longer in service.   the phone is new, but same number and same service.   my friends sprint phone had no problem calling the same number before now.  and it goes to a Verizon message and it's not even a verizon service on th phone.  he can send and recieve text messages with me and I can call his Sprint phone and it go through; but he cannot call my phone???????????????   Any idea why?   Jacob Stanley 858-205-8210