Only 2 of my 5 data bytes actually worked correctly. The other times my data was used instead. I called support the first time and was told the data bytes were only to be used 24 hours after the last one finished, which is not what it leads you to believe in the terms and conditions, which state 24 hours after activation. The other times i would start a data byte session but the data was still being used from my regular account.
Thanks for the update @Jacrand!
A Data Bytes session can only be activated every 24 hours, if 24 hours haven't passed then it won't allow you to activate a session.
That said, if you activated a session and noticed that data was taken from your data bucket we are aware that in very rare cases this may happen. Not to worry though, as we're aware a fix is in place and you won't be impacted on your invoice. Everything will be adjusted automatically
I hope this helps!