Vodacom contract upgrade

My contract expired. Vodacom phoned me saying that i should upgrade. I asked for a contract renewal on my number only, no phone upgrade. I opted for the Red Flexi 170 Plan. The Vodacom agent said i get a phone for free because of my loyalty and years as a client with Vodacom. I asked if i have to pay for the phone because i did not want it and he assured me that the phone is for free. The first invoice i get lists a handset installment and i get billed R80 for delivery of the phone. The contract i signed up for was for R170 per month and my first invoice is for R301.99. I queried the amount and was told they will get back to me. Ms Pillay from Vodacom said they are handing my account to the collections department after i said to her in a email, that i have used the phone and will not be sending it back. My account with Vodacom is on debit order and they will just debit my bank account with their amount. I i refuse the db order, my credit score is affected. Can someone listen to the recording? What do i do now?