Phantom charges

I bought my iPhone 7 from the MTN Hyde Park in January 2017 on contract. I queried a charge on my statement or roughly R90 for iPhone for life back in May 2018. I was sent from pillar to post until someone eventually told me to approach iPhone on this matter. I don’t understand why since MTN not iPhone has been deducting this amount from my account. Anyways I approached iPhone and they explained the concept. Turns out I don’t even qualify for this iPhone for life since my package is specifically excluded from the deal. They referred me back to MTN as I’m not their customer essentially, understandably so.

I now went back to MTN to tell them the issue and AGAIN after moving from one clueless person to another I was told to speak to the branch that sold the device for me. ? Went back to the branch whom are just if not even more clueless. I was told some nonsense that I signed up for it. How can I sign up for something I don’t even know about? Even worse how do I sign up for a promotion I DON’T EVEN QAULIFY FOR?!? This is stupid!!! Eventually after back and forth for a week she logged a query.

I haven’t heard from MTN since.

How can MTN add charges and deduct money from my account and not know what it’s for? Where is this money going? When asked about it, your employees don’t know either? I’ve been a customer for over 10 years and this is how I’m treated?