Villager despawn

Dear Mojang,

Kindly requesting you to fix villager despawn bug. I have created a Minecraft village near my base, and have brought in 2 villagers. After few days, both of them disappeared. I have locked them in before finishing my village and have lit the place up so that hostile mobs don't spawn, However, they disappear mysteriously. Generally, villlagers do not despawn once a player enters a village, unless attacked by mobs. Requesting you to fix this bug. Thank you for your consideration. We hope to see a fix in the bug soon. 

Kindly asking you not to ignore...