A simple misunderstanding and so much goes wrong :(
As Mark said, we can refund it for you if you like, however here is the situation:
So instead, after discussion with some other users, we opted to remove the functionality from the core, and put it into plugins.
Why? Because you can reorder plugins to suit your needs. But you can't reorder the component's execution order on every site.
The down side to this is that the plugins are no longer rendered by default, but what you can do is add a function to the plugins ( onPrepareNinjaRSSFeedRow or onPrepareNinjaRSSFeed ) you want to render that executes when Ninja RSS is processing the feed content, then use the feed stripper plugin to strip out the tags you don't want to render.
If you download our Enclosure plugin, or Ninja Access, you will see the new function name inside them. Alternatively, if it's just 1-3 plugins you want to activate, email them to me at daniel at this site and I can fix them for you.
I know it's a hassle, and I apologise, but I had 1/3 of our members wanting to strip tags completely before executing, 1/3 wanting to execute all plugins, and 1/3 wanting to execute some plugins but not all.
This was the only way to give everyone what they wanted.
p.s. you can feel free to encourage the makers of those content plugins to support Ninja RSS :p