Returned router

Terrible service!

Was called and offered the WiFi package. Upon receipt, the router did not connect to the internet. I went to an MTN store in Tygervalley, a few days later and they told that there was no coverage in the area. They then took the router and returned it to the warehouse and gave me the IRMS no: ***. The device was returned as it was received, not even used once. The MTN consultant at the store from which it was returned is that one that confirmed that there is no coverage The coverage department says coverage in the area but the device was not connecting to the internet, hence returned. Been trying to cancel this since September. I'm tired of paying for something I don't have and being taken back and forth I even have proof from the MTN store returned the router months ago but I am still being charged for a router I do not have. I'm being told that the investigation was invalid but I'm still being billed!