Just got charged $900!!!

HI I've just been charged $900 for box.  I am searching everywhere and cannot find a billing page or any invoices to understand what this charge is for.  It looks like I am supposed to be on a free account.  Last month I tried to start a business account, but got no support to understand what it was for and how it was different and I cancelled it.  I need to know asap what this charge is for.  I'm also astonished as the inability to reach anyone or find any information on my own account as to why I am being billed and for what.  The product is great, the lack of support needs to be fixed.