Someone changed my php version for my magento 2 website to 5.6 and I changed it back to 7.0 and now I'm getting this error when I try to run the major magento commands such as compile and system:upgrade

The file "/var/www/vhosts/ooples.com/httpdocs/var/generation/Composer/Console/ApplicationFactory.php" cannot be deleted Warning!unlink(/var/www/vhosts/ooples.com/httpdocs/var/generation/Composer/Console/ApplicationFactory.php): Permission denied#0 /var/www/vhosts/ooples.com/httpdocs/lib/internal/Magento/Framework/Filesystem/Driver/File.php(405): Magento\Framework\Filesystem\Driver\File->deleteFile('/var/www/vhosts...') #1 /var/www/vhosts/ooples.com/httpdocs/lib/internal/Magento/Framework/Filesystem/Driver/File.php(403): Magento\Framework\Filesystem\Driver\File->deleteDirectory('/var/www/vhosts...') #2 /var/www/vhosts/ooples.com/httpdocs/lib/internal/Magento/Framework/Filesystem/Driver/File.php(403): Magento\Framework\Filesystem\Driver\File->deleteDirectory('/var/www/vhosts...') #3 /var/www/vhosts/ooples.com/httpdocs/setup/src/Magento/Setup/Console/CompilerPreparation.php(68): Magento\Framework\Filesystem\Driver\File->deleteDirectory('/var/www/vhosts...') #4 /var/www/vhosts/ooples.com/httpdocs/lib/internal/Magento/Framework/Console/Cli.php(74): Magento\Setup\Console\CompilerPreparation->handleCompilerEnvironment() #5 /var/www/vhosts/ooples.com/httpdocs/bin/magento(22): Magento\Framework\Console\Cli->__construct('Magento CLI') #6 {main}

PHP Fatal error: Uncaught Error: Class 'Cli' not found in /var/www/vhosts/ooples.com/httpdocs/bin/magento:31 Stack trace: #0 {main} thrown in /var/www/vhosts/ooples.com/httpdocs/bin/magento on line 31

Fatal error: Uncaught Error: Class 'Cli' not found in /var/www/vhosts/ooples.com/httpdocs/bin/magento:31 Stack trace: #0 {main} thrown in /var/www/vhosts/ooples.com/httpdocs/bin/magento on line 31

What can I do to fix this error?