How do I change the bandwidth warning email address?

Is it possible to add or change the email address which gets sent the bandwidth limit warning emails when I approach my monthly limit of 30GB?

You can change the email address we send your communications to via the portal, though that will change it for all communication (not just for the bandwidth notification emails). We can't offer separate addresses for different communications I'm afraid.

Thanks, I've changed it now.

I unexpectedly went over my monthly limit of 30GB this month which meant my internet was cut off. When I phoned plusnet to sort it out I was offered an extra 5GB for £5.
I agreed to it and my internet was reconnected with an extra 5GB allowance, which will be fine until my next billing period which is the 2nd of April.

However, when I look at my account summary in the portal, my product seems to have changed to "PlusNet Broadband Your Way Option 3 with included 35GB bandwidth" which is £24.95 per month instead of the normal 30GB allowance/£19.95 per month I was paying before.
I only wanted that extra 5GB to be a one off and I don't want to start being charged £24.95 a month.
I've tried to change it back to 30GB/£19.95 but it keeps changing itself back.

How do I change it back before my next billing date?

I'm only guessing but maybe you can only change it back in the next billing month which starts 2nd April?

I thought £5 for 5GB started 12th April and until then it was the same as always.