MTN data mobile contract sucks

In 2023 November around black Friday I changed my MTN SIM card to a contract of 18 months, which comes with a monthly 200GB which was advertised to be priced at R300. To my surprise, I was debited R545 and R746. this is beyond frustrating and extremely inconveniencing because I only budgeted for the advertised amount. i wouldn't recommend this for anyone