Buried (2010) on Netflix

Plot summary

The last truck in a convoy through Iraq is driven by Paul Conroy, an American civilian working for the contractor Creston Rowland & Thomas. The convoy is attacked, and Paul comes to gagged and bound inside a handmade wooden coffin, locked in with a lighter, a pen and a smartphone. The phone is set to Arabic script he cannot read and holds about sixty percent of its battery, left there so his captors can reach him. A caller named Jabir demands five million dollars by nine that evening. Paul spends the battery calling his wife in Michigan, the State Department and his employer, hunting for anyone who can find the buried box before the air runs out.