Get traction first, whether that’s from crowdfunding, presales, anything in between before even asking for funding. You’re trying to sell a high capital requirement company with no proof you know how to A) run it B) grow it

I think you should also start by not owning any aircraft of your own. There are countless companies you can contract to do the flights you sell. Operating like this will let you start without any capital and also prove to any investors that you are capable of both points A and B

I have to agree with this. Sounds like a trivial issue right now, you should be spending this time for getting more new customers instead of trying to convert people into from the rare few customers that are gaming the system. This is even assuming they would convert to paying customers instead of just stop using your product.