When you post a resource response, the points are assigned to your response based on the length of your response. It is just the same as the points acquired for your forum threads or respons. But, when an editor reviews your resource response, he/she will assess it based on the relevance and quality. And as such, may decide to hike or reduce the points (along with cash credits) as the case may be.
In your case, the points are reduced because your responses do not add any extra value to the resource posted and that could be the reason your points are reduced. I would advice you to kindly improve your language skills and post some quality responses to the resources. Add some extra value to the resource by providing some additional info.
To explain it to you in clear language - if I post a response to a resource which goes like " a very good analysis. Your language and explanations have made it clear to me ....." and goes on for long length, I'll get 5 points instantly. But when the editor reviews it, the points will be reduced to zero - because I've not added anything useful to the resources.
Hope your doubts are cleared now.
Live....and Let Live!
The problem with your responses to articles is that they are not at all clear nor do they add any extra value to the article. A response should be such that it is adding some more information on the article topic, thereby adding good additional content to the page. Your responses are merely repeating some facts already provided in the article and thus not adding any value. Additionally, you need to drastically improve your English skills. You could use online grammar tools and work on your English. Sorry to say, overall your responses are of poor quality and hence a lot of them have got rejected.