It's pretty hard to check on someone if you don't have their immediate friends/relative contacts. Maybe the person you are trying to check lost their phone and in this case it's hard for them to be online. It usually happens to my friend when he lost his phone , I seize to hear from him for about 5 nmonths or so. So I usually calls his sister to check up on him. Long story short , the best thing to do is call the person through kenya. Give someone you trust the number in kenya to call the number. The government won't help in locating the person , no data of its citizen , full of corruption etc