2015 Hyundai elantra se

Oil light came on got an oil change from the
dealership.  Picked it up and oil light still on. Ask
the dealership about it, they said they couldn't get it
to turn off. But it should on its own. Still on 2 days
after and if flashes or flickers when acceleration to
get up to pass it goes off then comes back on.
Same if I use the slap shift from 6 down to 5 the oil
light goes off.