If you want to delete your call log, simply go into Phone, Call Log, hit the bottom right key on your phone, click Clear Call log. (If this option isn't available something must be wrong with your phone.)
If you want to delete your contacts, I think you'll have to either do each manually, by selecting Select Items, then select all or the contacts you wish to delete, then hit the trash can button on the bottom. If your contacts are synced, I'd recommend you disable sync under Accounts, or unlink the account, before going on a contact removing frenzy.
(Hope this helps in a nutshell, even though the problem appears to have been solved.)