Depending on how much is at stake here there is a site called swapd.co where a bunch of people advertise Instagram "unbanning services." Basically they bribe Facebook support employees to get your account back. Typically they run for a few hundred dollars. I think the site has a built in escrow system too so as long as you pay on site you should be protected.
I hope this goes viral so you don't have to do that but it's an option. Good luck.
This is not meant as a criticism of you by any means for providing the URL - you are providing an answer to a question by advising of an existing service - but the fact that this methodology has to exist in order for this option to be available to anyone is sick, and it also seems a de-motivator for any non-bribery-related legitimate path to ever be put in place.
Yeah I've commented on this [before](https://news.ycombinator.com/item?id=33040446). The other thing is that a lot of the people unbanned by these kinds of services really did deserve to be banned. Until people inside these companies start expressing skepticism about what the abuse/"risk" departments do and how they handle false positives nothing will change so I just see it as a necessary evil but fortunately it seems some Facebook employees in this thread offered to help.
Also, here are some examples (I have not used these services specifically but I have had positive interactions with this site overall). For reference most of the scams occur in the currency exchange section because there is no escrow there unlike the other sections.
I hope this goes viral so you don't have to do that but it's an option. Good luck.