MTN double debits.

MTN is just always a dissapointment. They debited R400 instead of R200 for my wifi router contract.. I communicated with them a week ago regarding the matter and I was told by them that they'll look into the matter as to why that was done and call me back. Until today they haven't. The least I want to do is waste my energy on calling them. Here's the reference they gave me ***. Hellopeter please help me.