Support for template add-on refused

I bought a template for Joomla through Themeforest today (8 Feb 2019). The theme came with a few add-ons which was a nice incentive to purchase the theme.

I installed the theme immediately as well as the add-ons. Upon using one of the add-ons, an error is thrown immediately. I have gone to the developer for the add-on for support but they have refused with stating the following:
“If you want to [work] with us you have to subscribe with our side because you know all have some rules.”

So, in effect, I have to subscribe (purchase) twice to get any support for this add-on.

How do I get around this?

Support for bundled plugins or extensions needs to come from the theme author NOT the add-on author

Okay, cool. I’ll seek them out.