VXOC Astra-J/GTC

hi all
i bought a vauxhall Astra 2013 its cat D recorded (just one door was damaged and has been replaced ) but now i have problem with the fuel warning it comes up and when i go the the patrol station to fill it up i find the tank still halfway full
does anyone have this problem before or any idea how to sort it out?
also i would like to know if the car still under warranty or the damage has a voided it? because im thinking to take it back to vauxhall ( i have proof of the previous door damaged and its only the door so nothing to do with the rest of the car)
please advise
thank you

You should still be covered but any problems with the area of old damage would not it just sounds like I faulty sensor hopefully

I would say a faulty sensor.

I moved this thread to the correct section.