Use command:

command fc "$@"

This will ensure that no function called fc is called.

Style: The diagnostic message should go to the standard error stream and the function should return a non-zero status when failing:

echo 'Sorry, can not do that' >&2
return 1

Use builtin:

builtin fc "$@"

This will ensure that the built-in fc command is called.

Style: The diagnostic message should go to the standard error stream and the function should return a non-zero status when failing:

echo 'Sorry, can not do that' >&2
return 1