MRP Account

In January 2022, all of a sudden a received a very high account from MRP mobile. I phoned and disputed the amount. The agent told me it was an additional R400 data I used in December. Now, I have wifi. I do, not use additional data. So, I asked for a statement, invoice and itemized billing. I have already sent 7 e-mails asking for this. But I do not get any assistance from MRP Mobile. I just discovered I have only a limit of R200.00 so how did my account got to R554.00?