bring it back to whomever did the oil change and demand that they reset it properly. or google for the reset procedure and DIY.
its not an issue with the car, whoever reset it f'ed it up.
Past: 2001 330i ZSP/ZPP/Step
Past: 2004 S60R 6MT Sport
Past: 2007 335i 6MT ZSP/ZCW/322/655
Past: 2010 335xi ZMP/ZCW/ZPP/PPK/PE
Present: 2013 335i 6MT ZMM/ZDH/ZTP/3AG/494/508
Current Homeland Threat Level: