Do not upgrade when MTN says you can

So MTN emails me and phones me advising that I am eligible for an upgrade. So I decide to the upgrade online, eventually received the devices after numerous calls confirming my address. As per normal I receive my bill a few days before the debit order day and to my surprise there is an additional amount for "Early Termination" of about 800. So I was charged for upgrading in the 21st month but nowhere during the upgrade was I warned that I be paying an Early Termination fee. So why inform me that I can upgrade but not tell me that if I do there is additional costs. And when you send them a email complaining about the *******, they repsond saying "thank you for the feedback, it helps them improve their process", I didn't ask for that, I want my money back , not some useless response.