CB Billing Issue

I've lost a few quid somewhere between my bank account and actual accounts. Sitting here doing the very boring job of cross referencing bank statements to purchases I've spotted something with CB's billing.

My June invoice states I was charged one amount yet the actual amount collected from my card was £3 more.... On my account it's PUR000441 where you can see the invoice downloaded from the website and then attached. Card transaction was on the 27th June 2014.

If you need more details please drop me an email so it can be taken off the public boards....