That happened to me also where I didn't recieve an email but when i logged on to my carvana account, i saw they had processed all my paperwork and was just waiting for me to select a date for pick up and payment. Might want to try that if you haven't?
My pick up was yesterday, the driver text me 2 hours before his arrival and arrived on time. The process took literally 20 mins.. he explained everything to me, i signed a few paperwork, he verified mileage and before he left with car my they deposited what they owed to me in my account. it was that easy!