Mtn contract

I have 4 months been inquiring about my payment. When I call they give me their collection email to send proof of payment thereafter no one contact me, now when I call and mention my ID number I get transferred from pillar to post the last consultant Esethu by customer care putted me on hold while Athole from accounts just hanged up on me. I want to cancel my contract I don't owe you anything contract ended last month but still sending me invoices.