Breach of contract because Router does not work

In December 2015 I app**** for the R199 package with a free router on a 2mb line. I received the router only to find that it drops the Wi-Fi signal constantly and therefore could not be used. I also tried linking the router to my CCTV but found that the router also did not work properly and was not linking. I immediately went and purchased a new Netgear router which till this day is working perfectly. I went on holiday in December and when I returned in January I contacted Mweb to cancel the services as the only reason I procured the services was because of a free router. Since the router is not working I don't require the service and won't pay for services promised which was not rendered. I was told that the Router would be collected and replaced. Nothing has been done for almost a month. Mweb has now debited my account which I have reversed. I will not pay for something that does not work. Please cancel this service and fetch your router. You are welcome to check the usage and you will see that there has been no usage on the line for some time now.