Lies all lies

Why lie? On the 4th of August, I got a call to do an upgrade on my cell phone. At the time I thought I was dealing with MTN directly (which only much later I realised was RewardsCo or aka Mondo). I said I only want to do a sim upgrade as I am still happy with my devices. I also said that I think I was still paying on my devices until November. The consultant told me that my devices were paid up a few months ago and that I should not have been paying, he then apparantly spoke to a supervisor and was told I should get a refund. So why lie? The following week I double-checked my invoices etc and saw that my devices were only going to be paid up in November. I then get an invoice from MTN, billing me R2817.39 excluding vat for early termination. I can't pay this off in 1 go, now I am fighting with RewardsCo and MTN to get this reversed and reverse the upgrade. I keep calling and keep being told that someone will contact me about this but still nothing.