Affordable Satellite Phones
I didn't realize satellite phones are becoming affordable. This place: http://www.satphonestore.com(external link, no financial relation) sells a refurbished Iridium/Motorola 9500 for $685.00 US and air time from $.85 to $1.85 a minute. Those minutes are comparable or less than international roaming charges for your cellular phone. And unlike your present mobile, this phone should work from anywhere in the world. Renting is also reasonable: $125 for three weeks and air time at $1.75 a minute. They ship the phone from Miami.
I know a mother whose daughter will soon be travelling to Gambia, both were worried about being out of touch. I think the Mom would have gladly paid three times the rental for the security of getting a call each day. Remember extra batteries, though, or a solar charger. Accessories are very expensive but the ability to communicate at all, regardless of price, is remarkable.