Free Printed Bible Study Booklets by Mail from United Church of God

The United Church of God, which has congregations in Lagos, Benin City and Owerri, sends its printed Bible study booklets by mail free of charge. Its Nigerian website says plainly that the publications are offered free, both online and by post, and that the work is funded by members and supporters, not by asking the public for money.
You choose booklets on the official ucg.org Bible Study Aids page. Titles include "Jesus Christ: The Real Story", "Jesus Christ: Saved by His Life", "Christ's Reign on Earth: What It Will Be Like" and "Sunset to Sunset: God's Sabbath Rest". Each has a "Request Free Print Copy" button. At checkout you enter your email and a shipping address, and Nigeria is in the country list. The order total is $0.00. There is a donation step, but you can simply select "No donation".
The booklets are written for ordinary readers, so they suit personal study or a church group. If you prefer to talk to someone first, the Lagos congregation's contact details are on ucg.org.ng.