Incorrect data plan activated and absurd billing

On the 13th of April 2021, I app**** for a MTN data contract for 120GB at R269 ( including the WiFi router ), on the 16th of April 2021 I received an email stating that the application has been approved, the sim card was then connected and data received on the 27th I assumed was Prorated. On the 31st of May 2021 my daughter received an email with the invoice and the statement stating that the amount I will be billed is R505.59, when she queried this on the 08th of June , the response was I am on MTN made for Home 30GB, MTN id delaying giving me response , the debit order was set for the 15th when I get paid, today is the 10th , I have sent emails requesting the sales call transcript and the reason behind the activation of 30 GB for R505.59 ??? this is not what I initially signed up for I NEED THIS RESOLVED AS SOON AS POSSIBLE !!!!!