Exceeded Limit On BBYW Option 2 - Confused

[#1]

I've just exceeded my 15GB monthly allowance for BBYW Option 2 but I'm confused how much extra usage I've bought.
VMBU on the portal says:
"You have exceeded your allowance. Your usage has been extended by 1GB - charged at £0.98 on your next bill (£0.98 per 1GB)." VMBU now shows that I have a paid for allowance of 16 GB.
I've also received an e-mail that says:
"You've now used up your product's broadband usage allowance of for this month. We've added a further 2 GB of usage for the month to your account, which will add a £2 charge to your next subscription charge."
Which one is right?
Bob

[#2]

looks like the default info for the new value an pro top up traiffs that email.
i would think your vmbu is telling the truth an the email is one of the many automated emails giving the wrong info to legacy customers

[#3]

Hi Bob,
Disregard the email - the information in the portal is correct.  Usage is added in 1GB chunks on your product.

[#4]

Thanks James. I much prefer to be able to buy extra capacity in 1GB chunks so that's good news.
I think you should sort the e-mails out though.
Bob