Once in a while towards the end of my billing cycle I get the textmessages from AT&T stating:
"More than XX% of your 3GB of data has been used. If 100% is used we'll add 1GB of data for $10"
My question is, what if this is added with only 2 days left in my billing cycle - does the extra GB become null and void (whatever wasn't used) when the new billing cycle starts? If I only use, say, 150KB of the added 1GB - did I just spend $10 for 150KB?
Thank you! 