I'm not saying you'll pass, I'm teaching you how to prepare in a week and maybe eke by. You already spent the money, you might as well give it a shot.
Let me be clear: I don't advocate this. It's important to give yourself time to study. BEC should take between 64 and 80 hours to prepare for. There are 168 hours in a week – work = 128 (our friend with a week to study for BEC – who requests to remain anonymous – is in tax so he has about 110) – sleeping 6 hours a night = 86 so if you don't waste any waking hours commuting or eating, you can do it. You shouldn't. If nothing else, you'll know what to expect on the exam in the next window. If you don't study at all, try to retain what you can when you sit for this exam that you're not ready for. Even though the AICPA BoE switches questions up from window to window and your next exam will be a little different, just go and pay attention. There is a small chance you can pass. Do you know nothing about variance analysis? Clueless on economics? Your chances at passing will be smaller though I won't pretend to have actual figures on that. The better your foundation, the easier it will be for you to fudge your way through it in a week.
If you're going into it blind, you're probably not going to do well so focus on what came up on the exam. Using the example above (or whatever your work/sleep/live schedule is), focus your attention on doing as many MCQ as possible. Even if you don't understand them, sometimes working through them will make things click. You can try a cram course but your brain learns in layers so you can't approach this like a final you didn't study for. Sorry to be the bearer of bad news, that's just what I know. The best piece of advice I can give you is to plan better next time.
Don't pay for all 4 parts with one NTS unless you have a huge block of time to take exam after exam. Got it?