Deleted pst files.

Recently as a Support Agent my first call of the morning after “discussing” with my x all night I accidently advised a client to delete all of his .pst files while in the back of my mind I meant .tmp . Before I could think to tell him to go to edit and hit undo the damage was done. Needless to say no one was too happy with me and I was released from my contract without warning or reason. Out of curiosity would anyone out there possibly know of a way to recover .pst files. Is there a data recovery tool that could do the job maybe? Any advice would be appreciated.
jb