I have one contact who I speak to fairly regularly, but within the past few months, more and more of his calls to me are being dropped. He has called me from multiple phones in multiple places, and none of his calls come through. He says the phone rings and it goes to my voicemail, and he leaves me messages which I never get. Everyone else's calls seem to come through fine. Also, none of his texts come through either. He recently bought a Verizon prepaid phone in case it was a problem with the Boost mobile phone he was using, but that never worked at all. He's tried landlines and business phones, too, to no avail. Any suggestions would be greatly appreciated!