I would suggest that, instead of trying to complain about the people copying your products, which I think is practically impossible to avoid, and even from your own experience preventing it has led nowhere so far, you should focus on making sure that your version of the product is the best one. So that the people will naturally use it instead of those repackaged versions.

> take the Javascript code from my website, remove all ads from it

I would assume that this might be one of the reasons why people are modifying and repackaging your product. I would suggest to remove that incentive. So that the people will have no reason to repackage your product because it has annoying features. And so that they could use it directly and be happy about it.