MTN frustrating a client

MTN is frustrating me. I am very annoyed with the customer service by MTN consultants. I was advised to return my mtn month to month uncapped fibre rooter to an mtn store after migrating to another one with the same mtn. They gave me an IRMS number and told me to call mtn to ensure cancelation is done. Apparently I've been calling mtn for hours and no consultants was able to assist. They transferred me from one consultants to the other. They transferred me to mondo and mondo transferred me back to mtn. I spoke to 6 consultants but no one could assist. I am frustrated and don't know what to do to cancel the rooter. The story started when I went to deliver the rooter to a store. I went to a store in Mamelodi and they refuse to take it claiming that they cannot take it since I took it online while the stores are there. It seemed as if they were punishing me for using online services. I decided to call mtn again where I was given an mtn store in Menlyn mall to return it to. The Menlyn consultant took it and gave me a number to call ***. They are failing clients. I've been with different networks but all of them were professional,but mtn is a **** when it comes to customer service. I need help .