I would like to receive a summary report:
Tick Daily
And enter email and tick 80% and 100%
Then from tommorow you will receive daily emails telling you how much percentage you use, just minus that amount against 100...eg: 100% - 20%(used) . you will have 80% left
Simple then times that against 3gigs(3072) = 3072 X 80% =2457.6
That will be the left MB in your Account for that month