Any membership bundled allowances expire when the membership expires even if they were not used up.
Membership bundled allowances never carry over from one membership month to another.
(Just to clarify CASH credit does not expire/disappear and remains on your account until used to pay for purchases or services).
Add-ons are different.
They last at least a month from the date of purchase (which may or may not be the membership start/end date).
And any add-ons active when a new membership starts are extended to the end of that membership month.
So basically an add-on will last for between one and two months after which any unused allowance balance is lost.
Why have you got 13.8GB of a data allowance?
Seems odd/high.
Don membership comes with 8GB so you would have had to have Don membership and bought at least a couple of data add-ons to have that allowance as far as I can see...?
Hope this helps.
