Supersonic is a ****!!!!

What are these guys trying to pull??? Supersonic phoned me and offered me one month free trail. After one month I unplugged their router and phoned them to collect it. I paid installation fee for Vuma Tell as per agreement. They keep sending me invoices 4 months later although I phone them every month to collect their router. Now I have spoken to a supervisor and they recon I must pay R3000 cancellation fee. What happened to one month free trail period? Never signed contract and all the supervisor tells me that when i signed installation job card i agreed to their terms and conditions that is not on job card. Careful of these ******!!!!!!