Brighthouse Spectrum Do you pay for unauthorized charges? Internet

 I enter into Brighthouse contract for $99 per month after which it increased to $200 per month without notification. I contacted Brighthouse to cancel but they stated that I am in a contract. I filed a bbb complaint and Brighthouse responded Yes they charged me without notification and the employee will be retrained, and my balance is $0. Then $624 was submitted by a collection agency (credit protect association). I attempted to file a complaint but when I pressed the file a complaint button the hone automatically hangs up. I contacted Brighthouse and they said I owed the $624 which were not the service charge agreement.