Cam, if you've logged the issue before the warranty expired and they haven't resolved it you should be fine. Hopefully you got the supervisors name from the last call and can contact them directly going forward or at least be transferred to them immediately.
You should tell them that the unit needs to be replaced if they cannot fix it after this service visit as you've been put out and passed over for too long. Ask that they message their system with all of your past calls, issues and grievances. Have them read back to you what was entered and better yet provide you with a copy.
Good luck.
