Cartrack and its unheard of canceling fee

I recently surrendered my vehicle back to the bank now I'm in a process of canceling my tracking polocy with cartrack which is absolutely not going well reason being I've been paying an amount of 170 per month for more than six months now when I want to cancel I'm told a cancelation fee of 1700 applies this is so unheard of this company really operates in a doggy way all of this was never explaind to me all they wanted was my money which they got...I'm really trying to do things right but this company is forcing my hand really disappointed in this company.