I believe the modem, whether 3G+ or gsm has a software (dashboard) that keeps a record of your total uploads plus downloads. Alternatively if you are using orange gsm, you can configure a bluetooth internet connection using your phone& laptop or pc. The phone keeps a record of all downloads + upload data but this only works well with nokia Eseries and Nseries. I however believe orange bill their internet usage with a high degree of accuracy. The scammer are zain who calculate 1Mb=1000kb instead of 1024kb