size help?

I am running Zen with a cpanel hosting control and have exceded my server size. when I went to check as I shouldnt have exceded with the files I have I have found several files named core.xxxxx (xx is a number). These seem to be posible backup which are taking up loads of disk space.

Could anyone tell me where to change the settings in CPanel to stop this filling up my disk space. I back up my database to my local drive regularly and have a local backup of my zen cart in case of problems.

I need to know where they came from and how to stop these files filling up my server space please.

Files that start with core.xxxx are files caused by your server crashing. Yell at your host some more.