Sjourney on "[Plugin: WooCommerce - excelling eCommerce] Why are the order statuses (payment_status) not “completed?”"

I had a similar issue.
What does your order (#1599) showing within the woocommerce orders GUI display as the problem ?
My issue I was using a different default paypal "receiving email" address then I stated, the email address I receive my paypal funds to.
For example, instead of my default which was a blah@gmail.com address; I was using services@mysite.com so woocommerce saw this and perhaps because of the incongruity it (within the settings) it puts the order on pending.