Bad service after more that 20y a client

We are a client of Vodacom for over 20 years with 7 contracts. 15th Feb '15, I went to renew my contract. Monday evening my phone charged and Tuesday morning saw him lose power 30% within an hour, could only report on the Saturday 21 Jan. (Within 7 days) The technician looked at the Sony E3 but said it had to be replaced because the battery sits inside the phone. I have to speak to the sales person . The manageress (very rude, I was very upset) informs that the phone must be sent away, after the technician informed me that the phone needs to be replaced. (Why is there a technician) The phone went off and they borrowed me an old phone. Phoned Vodacom March 3 they do not know yet and I asked the number where I can find out. Call them but they could not track my Job card will not let me know. Two hours later no call back, call again and they are looking again and call me back in the next hour. Traced under something else and it's approved to get a new phone. Ilanga should contact them. Ilanga had no stock and hopefully in the week of March 9 to 13 nearly a month later and we just have to pay ..... Why can we not cancel the contract to try out another service provider. Our last upgrade