Con Artist

i've received a sms that i am eligible for an upgrade in september 2021 and of cause i needed the lastest Huawei Nova Phone. i called around and immediately fetched my phone the evening at the canal walk branch. the lady asked me what package i want and i agreed on the lowest one which was R449 for the next 36months. I repeatedly asked her if there is any charges that i need to pay and she said no charges i will be only paying the new contract come january month. With that said, it wasnt even long that i notice my bill was R1400+- and i tried calling the store but no one answers, then i emailed mtn and there response is that its for a migration fee and that mtn should have told me that. Like *** is up with miscommunication!!!!!!!! Then i called the store and the only thing they can say is sorry???? Is MTN conning people into signing deals? The following months mtn debited there amount and i just noticed that they pushed up my contract fee which enables me to think mtn is *****ing money during a pandemic because as far as i know the amount they deducting is not my contract amount.