Native WordPress Plugin as WooCommerce Helpdesk
We have already built a wordpress plugin which can be used as helpdesk for your WooCommerce store.
The plugin integrates nicely with WooCommerce, in backend and front-end, has 2-way email integrations among other features.
As you would expect from a WordPress plugin, our plugin will not put limit on number of support team members (users), customers and tickets.
For more details - https://rtcamp.com/rtbiz/helpdesk/woocommerce-plugin-integration/
If you like this plugin, please vote up so WooThemes may consider adding it to WooCommerce addon repos. They are no longer accepting new addons and requires all new WooCommerce addons to be listed here as ideas so that they can see user interest before hand.
If you have any questions about rtBiz Helpdesk plugin, feel free to ask me. :-)