Can't Import Demo

I can’t import Life Coach demo as I keep getting the error below. My host says they’ve already set Max Exe Time to 400 seconds, but import didn’t work.

Please resolve these issues with your server configuration before importing any demo template: Maximum Execution Time (max_execution_time) : 0 seconds. Recommended max_execution_time should be at least 400 Seconds.

I have updated my wp-config.php and php.ini files, but that didn’t resolve the issue either.