Scammed on home security

A Telus agent by the name of Clay (whose number is conveniently not working anymore) came to our house and two phone plans + home security in the range of $110. Of course we said yes to this offer. Recently we got a call from a COLLECTION AGENCY telling us we owe over 1.5k in charges for the home security. This completely comes out of the blue because in our bills not one mention of home security is among the charges. We called Telus and talked to them about this. All they did was reduce the charges from 1500 to 300 and told us we have to continue to pay an extra $45 for the home security until February 2027. Absolutely unacceptable