You have to use a recovery tool in this situation. As 50GB file is too large, maybe you will be charged. Despite of this, you can choose one or more to have a try. MiniTool power data recovery, recuva, Stellar are available.
We specialize in data recovery from failed hard drives and RAID arrays among other professional data recovery services. This forum is dedicated to the sharing of information related to the field between other professionals. Our belief is that we are all more successful if we share our knowledge rather than try to keep it all locked up as a secret.