They dont have Backup for this PDs since this PDS belongs to Test Region ..
Suggest there should be disaster backups for test environments as well as production. . . It does not sound like good business to be willing to lose the environment where new development and production enhancement/repair is done. . .
You might ask if there are any full-volume dumps that have been taken and retrievem the pdsmfrom this.
Actually Why COPY is wotking like this ? Whats the diff b/w COPY & 3.3 option ?
I'm not connected to a mainframe now but i do not know which "copy" was used. When i want to copy a pds, i use 3.3.
Suggest you create a throw-away pds and go to the COPY you used. Then use PF1 and see what info is presented. There may be something about how the target dataset is created.
Not knowing what you have, i can't suggest how to "un-collapse" the file.
You might also look at the "info" about the problem dataset and one that is not damaged. This may show something.