The problem isn't their use of WP, it's their use of the WordPress and WooCommerce trademarks.
Besides, that’s BS and if you don’t already know it you need to speak with a competent attorney. Trademarks must be defended in a timely manner to be maintained, and they’ve been using those terms for years. That ship has sailed.
Stop digging yourself a deeper hole and start thinking about what you can do to repair the goodwill you’re burning.