Why is my bill not what my contract says, even though I have not used anything extra?

[Teflon]

I have two accounts and neither are charged the correct amount.  I'm being charge 54p too much on one and 94p too much on another. Zero extra charges on both bills. Previously, the correct amount was charged.

Anyone got any ideas? Thanks

[Bambino · Accepted solution]

@Teflon It's most likely the April increase in the RPI, which was 2.7%

[jonsie]

All networks do this.