No delivery yet billed for an upgrade

I went to the MTN Cascades store - where I have gone for most of my upgrades / new contracts. On this day at the end of July / beginning of August I app**** for an additional contract (for a Samsung S8 plus and a gear watch) and the upgrade of my current phone from a Sony Xperia Z5 to a Samsung S8.

At the end of August the Samsung S8 plus and the gear watch were delivered to me. No sign of the S8. Both contracts were done on the same day!

After waiting and waiting as I was told there were issues with the warehouse, then I was told the courier company had made an error and then back to the warehouse excuse - I finally decided to cancel the upgrade. I have been billed for TWO months for an upgrade but I still have my Sony! I have contacted the store and the MTN customer service to no avail. I then further tried to simply cancel my contract with MTN but have been told by the call centre that I have to pay the cancellation fee!!!

MTN are in effect *****ing my money and if I do a stop order - I will be the one that gets blacklisted - not them! It's a lose-lose for the consumer when it comes to poor communication and management within MTN itself.