This is an Arduino project that retrieves phonebook entries from the file system of a SIM800 module. The program was written to run on an Adafruit Feather Fona, but can be adapted to COMPATIBLE SIM800 modules. The phonebook must be loaded to the SIM800 module FIRST, which requires pairing your phone or device via bluetooth and syncing your contact list.
The pairing/syncing process is described in the post: http://thisoldgeek.blogspot.com/2016/11/sim800-bluetooth-sync-iphone-contacts.html