Annoying Weekly Marketing Calls

I have been a customer of cartrack since Sep 2023 and locked into a 36 month contract so I'm unable to close my account to stop the incessant calls to sell me a tracking device which they already fitted 2 years ago....rather use Tracker or Netstar, when I was with them I never received weekly calls trying sell me Dash Cams, a second tracking unit, etc...I assume they're financial difficulty as they sound extremely desperate... a cause of concern if my car is ******. I even changed my cell number on their system but this doesn't help, they harass you on the old and new number all the time.