Check if your theme has its own comment template by going to [yoursite.com]/wp-admin/theme-editor.php (when logged in as an administrator). Then look at the right column and try to find comments.php file. If it’s there, it controls the way your comments are displayed, so you can manually delete hyperlinks and dates from it.
If you can’t find date printed out in comments.php, go to functions.php and try to find it there (search for functions containing word “comments”). Try to find get_comment_date() or get_comment_time().
And before you delete any line of code – always backup the content of the files.