Class 'Presscore_Config' not found

I get the following error for the past 4 days while i try to open my website. My entire business relies on this website and i really dont know what to do. I tried to contact my developer few times but he ran away. Please guide me step by step to resolve this issue, as i’am not a developer pro but i know the basics. It would be very kind of you if you help me in resolving this issue.

Warning: include(/home/novaikpp/public_html/wp-content/themes/dt-the7/functions.php): failed to open stream: Permission denied in /home/novaikpp/public_html/wp-settings.php on line 329

Warning: include(): Failed opening ‘/home/novaikpp/public_html/wp-content/themes/dt-the7/functions.php’ for inclusion (include_path=’.:/usr/local/altphp54/lib/php’) in /home/novaikpp/public_html/wp-settings.php on line 329

Fatal error: Class ‘Presscore_Config’ not found in /home/novaikpp/public_html/wp-content/themes/dt-the7/page.php on line 17

NOTE – even when i open my dashboard, on the top of my dashboard i get this error. And i know the password and user name for my cPanel.

Thank you
Regards,
-Prasanna