Thanks, but I have no thanks for you; Thanks, but I'm not thankful for the offer. Both sounds rather rude, but I understand it's not the meaning. If however one uses a second comma: Thanks, but no, thanks, the correct implementation is revealed: Thanks, but no, I refuse the offer; thank you once again. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.