I purchased a used Galaxy 5 (with verizon network) online and gave to a friend as a gift; also, the phone did not come with a carrier SIM card. When my friend tried to activate the phone, she was told that the phone is locked and can only be unlocked by the previous owner. I have no idea who the previous owner is. How can we get this phone unlocked for activation? BTW, I am a Verizon service customer. Please advise.