I worked a while for phone customer service (don’t recommend even to my worst enemies) and we only gave nice stuff to angry people. Basically I couldn’t do anything on my level other than follow the script, but if they asked for a supervisor they usually they got their issues solved more quickly and with some free stuff included, so after that experience I always try to be polite at the beginning but if they are not being helpful I ask them to escalate my issue and play angry