Sorry to hear this, i had the very same experience.
2 weeks after a service and just as i was getting home the oil light came on. Parked up and discovered oil steadily dripping and accumulating along the undertray.
Apparently the gasket on the oil filter had 'failed' (not fitted correctly...?)
I filled with oil and it got me back to the dealer that did the service.
They rectified, steam cleaned the engine and replaced the oil i purchased.
I hope u get sorted to your satisfaction.