Updated Theme – Now have no access to website

I just logged into the wordpress dashboard, tried to updated the theme (which it stated was completed successfully) and now I cannot access my website or the wordpress dashboard. I contacted my host and they are unable to fix anything on their end.

They noted it to be a 500 error and tried changing PHP version to 7, but it didn’t work.

The following message is listed in the WP Admin folder:
[14-Aug-2019 23:56:14 UTC] PHP Fatal error: Can’t use function return value in write context in /home1/perfosd8/public_html/wp-content/themes/HighendWP/functions/template-parts.php on line 475.

Any help would be appreciated as I can no longer access my website.
Thank you.