Open a support ticket. They allow it sometimes
Pretty sure you can use paypal or your debit card to buy a pre-paid credit card. Then you can use the pre-paid credit card to buy the custom.
Or this.
Thanks for everything everyone! Just managed to order my custom! Ngl, it really feels like a gigantic blow to my wallet lol, and im not sure if im ever planning on doing it again, at least not untill i got a stable income and all that. Im excited for it though! It got everything i really need, i truly feel like this custom is gonna evolve me so much, and make college college so much better than it already is. I cant freaking wait.
You have the modules that can be reused if you decide on a new custom or for upgrading it to a new build (Q+ whenever it comes out).