Cancel my MTN subscription

Hi I'm furious as I type , Please assist me as I have left my router for repairs at MTN trade route mall. It's been over 1 month already and my router has not yet been sent for repairs as the consultant has been getting an error on his system when booking in my router. I can't be paying for something I dont have as it's not like I can use the Sim in a phone or even a pocket router as the consultant says my service will get suspended as it's only for a home router . If MTN cannot get my router fixed, I would like to have the service cancelled at no cost to me and I will be happy to go to another service provider. Kindly treat this matter with the urgency it deserves.