Just an update here, might help overs in the future.
Replaced oil level sensor, no change. Had a chat woth seat next door to me as vw/seat same in some ways, and a tech there told me he was aware of issues with the bonnet catch switch causing the same problem.
Basically oil level goes low, comes up on dash to fill up, you open bonnet (switch is stuck or broken) you top oil up to correct level but as the car hasnt seen the bonnet be open it doesnt turn the warning on dash off and reset. So i opened bonnet, traced switch wirring and it comes out to a connector above the o/s headlamp, i bridged a connection here incase the switch was done fore to make a circuit, closed bonnet, started car, job done.