Vodafone put prices up, by loads!
They've put a lot of prices up, for the times customers go outside of their packages. So if you go over your minutes, now you'll be paying 37.5p per minute. If you phone 084 numbers, that's gone from 19.17p a minute to 37.5p.
In fact, if you look at the changes, pretty much everything has been changed to 37.5p per minute.
Vodafone realise that this might make you want to ditch them, and say: "We appreciate this may mean your monthly bills increase by more than the Retail Price Index of 0.9 per cent, so we’re giving you the opportunity to end your agreement with us without charge. To do this, simply write to us within 30 days of the receipt of this communication at Vodafone Customer Care, Vodafone House, The Connection, Newbury, Berkshire RG14 2FN."
Of course, this isn't a charitable thing on Vodafone's part, but rather, a legal requirement that was introduced by Ofcom in 2014. Don't be thinking they do anything out of the goodness of their hearts.