Why's my amazon account under review and orders pending for nearly 2 days now?

I recently put a iPhone for sale on amazon, I've been buying on the site for years but this is my first sale. My item was brought but then I had a email saying my account is under review? And the order has been pending for days? Anybody experienced this?

The person who bought it might have complained. Don't sweat it, just give it a few more days and if it still isn't sorted contact them