Unable to cancel contract

Once again, vodacom let me down. I took a new online contract with an iphone 13,3 weeks ago. Vodacom claims if not happy with package, the device can be returned for a contract cancellation. I have been trying for the last 2 weeks to return the device. 6 phone calls, every time, no return is logged. The agent says vodacom does not have an online system for returns. An email is sent to courier company to collect. Very outdated system for a high tech network company. I am concerned return time will run out and I will not be able to cancel the contract Ravi