Incompetence

On 8 Jan 2016 a router was incorrectly delivered to me. I contact Cell C immediately and they promised to arrange to have it collected. After numerous calls after that they finally collected it via RAM couriers on 17 Febr 2106. Since then I called Cell C every 2 nd day to find out was is happening about the returned parcel and cancellation of the contract. With all the necessary ref numbers and what have you they always transferring me back and forth and with that being cut off . Phone again and still nothing can be finalized. On the 7th Feb a Wendy promised me that everything is sorted out and she will contact me confirming it. However today I received another bill on that contract without even being having that equipment. I also contacted them again today with transfers back and forth with no success. Always only promises but no actual progress to solve this problem and get the refund for the incorrectly billing. Can anyone please assist.