no help billing and return

I got an upgrade on 04/10/2017 - when receiving the router i realised i would not use it and phoned MTN to get it collected and change my upgrade package - i have phoned the upgrade people 5 times - 1st time they told me to take it to MTN and they will cancel the upgrade - i went to Greenstone they said they cant help - 2nd time i got told to put down the phone and keep trying until i get hold of the Durban branch - then i got told to get hold of their courier and arrange collection , which cant help anyway, while this is going on i get my bill where they haven't deducted the 140 discount - so i query that - i have phoned 808, 10 times even spoken to a manager and still nothing is getting done - every time i send an email to customer care it gets forwarded to retentions and i get another reference number - i have now called 808 and got told there is a problem with their systems can i call back later - this service is terrible , i do not know how else to get any service - it is going on over a month and no help or not even a phone call !!! extremely frustrating