I know you are all going to think I am crazy, but I will post anyway.
If it cannot be professionally fixed, I would try craft paint mixed with water.
Before you say no, or call me nuts, I have done it with great results.
First I would see if can be fixed, but if it can't, it is all already kinda sorta ruined.
I would find metallic paint the same color, or as close as you can find, mix some with a little water, then use you finger to rub it in. Clean off any mixture that gets on the good part of the bag.
You may have to go over the spots a few times. You have to let it dry between coats.
It will never be perfect, but it may work enough that you don't notice the damage unless you look for it.
It would be a "last resort" fix, but it worked for me on a paddy.