OP: I suggest being MUCH more transparent when asking for help.
For all we know you are running a scam center support app. Consider the outraged posts that make it to the front page, essentially complaining about how their MLM bitcoin scam has been shut down.
They can kick you out and make your software the equivalent of bricked hardware; without any means to appeal their decisions.
How hard it will be to rewrite it for the web?
If it's react native or flutter probably not that hard, you can go back online with some struggle, but it's at least a way.
Claiming you fired the party responsible isn’t very convincing, honestly, especially if it’s hard to verify: was it an alias? did the employee only exist on paper? are they still around just not “employeed”, were they a designated patsy? Nor are claims that you revamped your security, which doesn’t address the root problem of whether it was intentional behaviour or not. And what’s worse, the natural urgency and appeals to emotion that you include in your story are unfortunately widely used tactics by scammers to try to get a human to bend rules to their benefit, and reviewers are trained to treat them as such. You need hard evidence.
How can you demonstrate that you didn’t know what the employee was doing? Have you reported the employee to the police? Is there a criminal case you can point to? Simply having a bad process before could very easily have been an intentional way to avoid knowledge of wrong doing, another common tactic used by criminal orgs.
Best of luck.
I.e. all these "tech companies" that want to people to have accounts (and be heavily invested and/or dependent on them) should not be able to cancel those accounts without due process. This should be a legal requirement for them to operate at all.
Unfortunately, this is one of the risks of handing control over your future to the tyrants who run walled gardens.
While you can't undo the past, the silver lining of this experience is that it has clarified to you that Apple is an abusive, unfair, and unreasonable corporation that you should avoid doing business with.
As an immediate action, I'm sure it's not what you want to hear, but HTML5 and WASM have come a long way, and mobile web applications are increasingly converging on the capabilities of native mobile applications. While a rewrite will not be cheap or easy, ensuring you can offer service to your users without having to ask an abusive tyrant for permission ensures you are at less risk of this kind of tyranny and the disruption and harm it inflicts upon you and your users in the future.
I am sympathetic to the victims of Apple's tyranny (as well as Google's, Microsoft's, and others), and I know I can't solve the problem by myself, but I would like to help in a more material way - do you have a Bitcoin address I can send a donation to?