First of all, 400 hours is a lot.
On the other hand, it really comes down to what you were doing in those 400 hours.
If the vast majority of the time was spent testing stuff and submitting feedback and bug reports or whatever, then you should be able to get a refund, because most of the hours is not "play time," but rather you providing a service to the devs for free.
On the other hand, as others have pointed out, if most of the time you were playing and having fun with the game, then no, you don't deserve a refund.