When you replace the panel you have to know what shade of white you have (there are loads) assuming its white!! and it will usually cost quite a lot of money, £270 is usual for the repair man to visit.
First try some "Pollyfilla" in the hole. Put loads on then the following day chisel most of the excess off then sand it carefully. You won't hardly be able to see it and this might do for you.
One thing be careful cleaning the door in that area as the powder will mark if you smear it with dirt...only use water.
But if you do then re polly it again.
It worked for me.....Good luck!
Bob the Builder, February 2005