MTN too busy to talk to you

I received my MTN bill where an amount of R565,20 for 'data charges' was included on my bill. I do not normally purchase data as I have a monthly bundle, but due to necessity during a holiday in July I needed to purchase an extra bundle. After several unsuccessful attempts to purchase it via MTN services I eventually purchased one via my banking app, so I queried these 'data charges' via direct message on twitter, quoting both the invoice number as well as my account number. I was asked for my ID number and my MTN pin, and I gave my ID number but said that I could not remember my pin. No response after that, nothing.

I then sent the same message on Facebook. After this also received no response. I then posted the query directly onto the MTN page and got a response along the lines of 'we're busy, we'll get back to you', which they still haven't, 4 days later...

This is not a complicated question I'm asking. I'm merely querying an amount on my bill. Why does MTN not want to talk to me?