Please refer to this guide to understand how to read the usage display for Internet Top-up and Roaming Pass purchases with validity that cuts across bill cycles.
From the example illustration above, if you have purchased a pass on 5 March with a 30-day validity in the middle of your current bill cycle which will also cut into your next bill cycle, the GB used resets according to the balance GB left once the bill runs.
In the case of the example above, if you have a balance of 2.70 GB on your internet top-up/ roaming pass purchase prior to the bill run date, the GB used will be reset to 0 GB once the bill runs to date. This GB used should be read in relation to the remaining GB balance prior to the bill run date and not the overall GB allocated for the respective pass that was purchased.