More information is needed. Its unclear whether you were issued a new I-94. Are you sure that you requested an extension of stay? If so, then a new I-94 should indicate that your stay was extended until 2016. If not, then you may have to get a new visa stamp in your home country.
This will take a bit of preparation, so contact the attorney who filed the petition or consider hiring a competent immigration and visa attorney.
This is general information, not legal advice, and does not create an attorney client relationship.
If your H-1B was "transferred" and valid until 2016, then you I-94 should be valid for the same duration, unless your attorney did not file for an extension of status. Consult with an immigration attorney for additional information.
If your transfer was approved, you should have a new I-94 which supersedes your previous one. If the new I94 has the same expiration date, you might need a correction. You can of course consult with your employers attorney.