Customer Service Rep Complaint

How do a file a complaint against a representative that was unprofessional when I called to disconnect my internet service? I recently signed up for internet service but it appears I was a victim of bait and switch.  Two people during the sign up and installation process told me the monthly cost excluding taxes would be 60 but it ended up being 80.  I called to disconnect and the person in the cancellation department interrogated me as if I didn’t have a right to cancel and questioned whether I reviewed my detail bill.  I felt her line of questioning was irrelevant to my request and it was demeaning.