Router Cancelation

Hi

I have a problem with Mtn , they called me earlier this year offering me a contract for a router.On the call I was told I could cancel it anytime and once the router arrived it was not working even Today it's still not working. I went to about 4 mtn stores ( O R TAMBO, East rand mall ,Germiston golden walk and meadowdale) and all of them are saying the same thing that I should call 135 and speak with an agent and they are unable to assist me because I bought the router online. I challenge anyone to call 135 and see if they'll get an agent. The are no agents available to assist as the result this matter has been a drag and they still invoice me for something that I am not using. I've wrote emails to the retention department and nothing has happened I even spoke to them on Facebook and they since been escalating the matter I even blocked their debit order because the router is not working and now this is affecting my credit record. I have all the documentation, emails and chats supporting my query I would like for them to arrange to get their router and advice on the cancelation payment because they kept charging me even though I was not using the router and ideally i shouldn't be paying for something that not working so how am eligible for a payment of something not working I'm willing to pay off the cancelation fees but I'm not willing to pay for the months when I was not able to use the device. I still have the device my request is for them to come and get their router I no longer want anything to do with MTN.