Very few workers in the U.S. have actual employment contracts. If you work in the tech sector in the U.S. you almost certainly don't. Instead, your employment is "at-will"; i.e. terminable by either party, with or without cause or notice (unless you live and work in Montana). You may have received a written offer of employment when you were hired (outlining your title, salary, hiring bonuses, etc.), but that is not an employment contract. The important distinction for the OP is that a written offer of employment is not legally binding. They can lie or change their minds.