ripoff and overcharging client on unlimited 24/7

Good day,

For the second month I am being over charged. Last month I requested an invoice for March that is gonna show what I paid the R821 for, the invoice needs to be detailed like : pay as you go, unlimited off peak and unlimited 24/7. how much did I pay for each. I have not received that. again the month of April I am still overcharged, this moth there were no changes done on my profile I am on unlimited 24/7 but I am charged R631 instead of R479. I am honestly getting tired of raising the same issue every month. if your unlimited 24/7 has a limit advise the customer. I need my refund of R153. I also need a detailed invoice that I have been requesting the whole of April.