Incorrect billing

I would like to query the invoice I received this month dated 13-02-2016<br> I seem to have been billed R5260.45<br> <br> I want you to send me the itemized billing as every time I use the modem I check for the available balance on my modem and it has never been 0.<br> I don't know how this got to that amount .I hardly use this modem and cannot believe he charges are a correct reflection on the use of the modem.<br> account A***<br> invoice E***