Good manners can get you far, opening doors that might otherwise remain closed.
For example, a courteous tone and a simple please or thank you can inspire call center employees to go above and beyond, even bend the rules to make your day a little brighter.
But as one story from the subreddit r/talesfromcallcenters reveals, some also use politeness with malicious intentions in mind. So be careful not to expose yourself to people too much, especially when your relationship is just transactional.