Poor service delivery

I have a contract with Vodacom for data ,I found out Vodacom consultant took an iPhone under my name without my consent in Brooklyn Pretoria,I have the documents that show my forged signature I am battling to cancel the initial contract because of Vodacom poor service delivery as a result I am expected to pay for the arrears accumulated because of their incompetence I am highly dissatisfied and I will not tire to talk about this it has been six months of going from one department to another with no success. I want Vodacom to cancel the contract effective immediately,I will not be a victim of their *****ing consultant