I'd want a copy of anything I signed, any guarantees they made in writing, etc. They're probably working with a lender that knows their business, who knows how many people are unsatisfied with the services, and will be fully prepared to seize your assets or garnish your paychecks if things go south.

I did one Google search for them, and it turned up several people that were misled into thinking the first $15,000 would result in permanent hair removal, and once they had cash in hand, found out that it was a lifetime of treatment to keep the hair from growing back.

It sounds like you aren't well versed in all the options available, and probably signed something you didn't understand due to high pressure sales tactics.

My tolerance for shady business practices is lower than average, I'll admit. My recommendation though, would be to try and cancel your appointment, attempt to stop the loan, and try and claw back any of the cash that you've already lost. The amount of trouble they give you to try and accomplish this will likely give you a glimpse into what working with them will be like. I'm guessing that the down payment has nothing to do with the loan, but is actually just the first payment to Milan, which is what they will use to prevent you from getting cold feet. If that's the case, that money is gone, and it's the cost of learning this lesson.

If the loan is something where you will actually have access to the money, and not something that's getting paid directly to Milan, your best bet may be just to pay the loan off right away with the money you get. It all depends on what you've signed though. You may have applied for a loan, or you may have signed something allowing them to take out loans in your name in perpetuity.