Where did this bill come from

I had a bill of I think 1200 odd last month, I paid in 1300, now I get an sms telling me I am in arrears and my bill is 2100. ***, I do not understand. I called into the call centre, useless AS PER USUAL, I said what is the 2100 for, no it is for your bill. What bill. No your bill. Ok dumb dee dee dumb da daa.<br> <br> Right, what is the 2100 for please. I know last month I downloaded 5gb data and YOU ACCIDENTALLY SENT ME 2 x 5GB data, which I said I would not be paying for the other 5GB.<br> <br> I am retrenched and unemployed, now what is the 2100 for please. Because I am monitoring this account like an owl.<br> <br> Kind regards<br> Valerie