Incorrect billing on data account not rectified

Our data account has amounted to R17k +- in one month. The total data cost over a 3month period was R46k. We requested a breakdown of the account - still not received. We requested that the amount be refunded - still no feedback. We wanted to know why a cap was not put on the account over 10gigs like they normally do - no feedback. We have emailed - phoned, been into the store. Dropped off letters authorizing that the info be given - to no avail. We are a ministry and this money should be going towards our welfare projects. It is unacceptable that we are mistreated in this manner and that MTN refuses to even respond. We would liek to know when this money will be refunded as (previously requested by the incumbent and the accounts department) and would like to understand why details of this account o date has not been received. Your urgent attention is required. It seems from our store issues that everyone has these issues!!!