The fuel filler flap won't open
 

hi all

I need help.
I own a mercedes E350 07 with AMG package 25000 miles.

I just replaced a tire at MB dealer and when i left the dealer i stopped by a gas station to get gas and i couldn't open the gas filler flap.

i know that the flap is closed when teh doors are locked but i unlocked the car and still the flap won't open.

Has anyone else had this problem is so what's the solution? is there a manual way to open the flap?

Please help

Instructions are in the owners manual.
Lock probably just went out, quick fix for the dealer.