Virgin O2 deal price not the same

[Fletspa]

Hi, I have been a Virignmedia customer for over 15 years and recently renegotiated a new deal which included an O2 sim for £25 per month. Received a number of emails from O2 about the account which became active on the 1st June and I have yet to use the O2 sim. I received a bill from O2 yesterday for £28.23, I have reviewed this online there are no add-ons. So why is the charge £3.23 more than the deal I signed up for? 

Anyone have similar issues or can help me understand this please?

Thanks

St

[pgn]

Weirdly, as it is now June, it could be the annual May RPI price increase, which this year was  7.8%:

https://www.o2.co.uk/prices, @Fletspa.