Checking the Plusnet Member Centre and going in the "Product Change" option, I was greeted by the message saying:
"Thanks - we'll start processing your product change request. Please note, as today is your billing date you might be charged for your old product until the new one can be activated. This will be calculated on a pro-rata basis and will appear on your next invoice."
However, I am still in contract and did not make a product change request. Is this just a systems error?