My friend from the UK has tried about thirty times to call m over about three days. I dont hear the calls coming through on my Android. When he does get through only about three times, then various Serbian phone numbers show up in my phone call log? And only once did his own UK number show up in my call log. My son also tried to phone me over the past few days, from Facebook Messenger and I could hear background noises, but not his voice. When I tried ro call back same. Yet everyone else who calls me can get through to me? Why do Serbian numbers show up? Why does it not ring on my side when my UK friend calls me. It does ring on my side when my son calls with Messenger from South Africa but we cant hear each other?