Terrible service from MTN

I receive data on the 12th of each month. I received 100GB data on 12 June and after 4 days it was gone. I have been trying to find out from MTN why it disappeared since I have only been browsing the internet and reading online books. eventually received the following message: "Can you kindly dial*180*87243# OK to have your data usage report for the past 30 days sent to your email address." I tried and received the message that no email address is associated to the number - even though I receive monthly bills for it.

I don't want to wait until the end of the month to get a month's data usage - I just want to know what has happened to the data during those 4 days. Apparently MTN cannot help me with this request so that it can be fixed asap. I wonder what their next excuse will be for the disappearing data. There is no way that 100 GB data can be used in less than 5 days.