I've had my share of conflicts with CSR's in my career but never lost one because I was the captain and doing, in my opinion, the right thing. One day I was about to get on the plane 30 minutes before departure and saw a United FO by the counter so said hello and was he jumpseating with us to Honduras. He said the CSR said it was weight limited so he and 25 passengers couldn't get on. I went to the computer and checked the wx and seeing it was the standard chance of showers, called dispatch and asked them to change it to a dry landing to get everyone on since I did the route frequently. They did and everybody got on. The CSR called my chief pilot and complained about my attitude. He never called me because he knew I didn't cause problems. We landed with clear skies and everybody was happy.
Hopefully things haven't degraded to this level since I retired 7 years ago in the US. I don't think so.