Write Wordpress/WooCommerce script to do a daily cronjob upload of inventory levels

I have a dropship site setup. I have several dropship vendors who provide an updated CSV product inventory file every day of product SKU# and Quantity. File can have up to 50,000 line items of SKU/Quantity. I have a basic script that will update the inventory quantity based on SKU# but for some reason it stops at about 2000 lines. Even with changing the max execution time. Need someone to rewrite a proper php or plugin to read a CSV file at specific times and update the database inventory quantity by SKU# Script is fairly simple, read each line and find the post_id based on the SKU# $sql = "SELECT * FROM wp_postmeta WHERE meta_key = '_sku' AND meta_value = '$sku' LIMIT 1" ; then update the stock quantity: update_post_meta($post_id, "_stock", $qty); Either a custom php script with cronjob or a WP plugin that has cron features to setup the WP cronjob.