Galaxy S7 Edge 64gb turned to 32gb after reset

A

AC Question

So I recently bought a Galaxy S7 edge which was labeled as having 64 gb of internal memory from a coworker who bought it from someone selling it from one of those buy/trade apps for a pretty good deal. I looked at all the information, even downloaded that "Genuine Galaxy" app and everything matched up. It said it was 64 go but after downloading no more than 3-4 apps I was already out of memory which was weird to me. So I decided to factory reset the phone and after it was done it checked the storage and it had 32 gb of internal memory instead. What in Tarnation happened to my phone. I still got it a a good deal comparing to how much it's being sold for currently but I need to know how Did I even lose internal storage space from resetting it and maybe if its possible to regain it. (For selling purposes because obviously it's more valuable with the 64 gb)