Hi one of their consultant phoned me about their new devices

Hi one of their consultant phoned me about their new devices. So because off the theft highest on Polo vivo I was interested. But I am already a client and want to downgrade on the current service to R99 and than get the new device. After my period of paying them for 3 years everymonth. One of the ladies in customerservices put the phone doen in my ear. My current device are working 100% why must I pay them R350 to come and disconnect something who is still in a working condition just to make money out of me