Restarting a DFPT calculation

Dear Users,

My DFPT calculation is stopped (not completed) and when I downloaded the files from server that were generated till then.
I looked up for continuation as well as reuse keywords which require a .check file to start. From the files I downloaded, I could not find any checkpoint files. I have .castep file from the run.

I would like to resume my calculation form the point of halt. Please suggest me.

Regards,
Phani.