Re: "despite me being very reasonable"
Sounds like another super entitled customer who doesn't understand the problem.
Moaning that there aren't enough people aren't answering phones is something that the support desk is well aware of, generally they're not the people who have any say in the decision.
Trying to short circuit by going to sales is just entitled "I'm too important to get in the queue with everyone else!!"
Trying to swamp their incoming lines is a serious dick move that helps absolutely no-one.