It's pretty tough to repair, and may not be possible. The only place I would try is rago brothers in Morristown, nj. Are you in the United States? I had a Gucci fabric bag repaired by them many years ago, as well as a wallet. They have a mail in service and will quote for free. I just used them for 2 lv bags.
I have seen them turn down repairs if it is not fixable. My guess is even if somewhat fixed it won't be perfect. My bag previously repaired years ago does not look great in other areas now. I used the bag to death but I am sorry it's not perfect.
I hate to say it but I think the fabric Gucci bags are not as long lasting as certain other bags.