ENGINE LIGHT STAYS ON

It is likely you will need to visit an auto repair shop for a FULL scan test .. Most parts stores can only read the codes related to engine performance .. Flashing D light is normally transmission related.

The fact they forgot to reset the oil life would not have any affect on a check engine light. Your first move is to the engine's computer scanned. Most auto parts stores will do this for free. Report back with the code and we can help further. Alex