detected that a fake bank card had been used maybe? You could perhaps ask them (though they would probably not want to reveal professional secrets/their own error)
Maybe going to a know scam, or some crook was caught for something else and found to be involved in your £25 or maybe something was bought out of character ?
it is fair enough JNO to name this company as I truly hadn't bought anything from them but did wonder when I looked at my online account thought it was dodgy looking but at £25 I just left it. Had it been more I definitely would have disputed it.
Everything Everywhere is EE, the mobile phone company.
I believe that when fraudsters are looking for targets they make small purchases, often phone top ups.
If they are successful, they know they have hit gold and go in for the big one. I think the banks know this, and probably were alerted by the unusual charge. It may be a computer programmed to spot this, and alert a human to look closer.
It's possible that the bank became aware (either through their own systems or through information provided by the police) that someone had managed to take £25 out of every one of thousands of accounts (and not just yours). Under such circumstances they'd automatically refund everyone, even if most of the account holders hadn't even noticed that the money was missing.
I have had £30 taken from my account some years back and it was top up mobile.
Also £600 as if I wouldn't have noticed that - my card number was used to let the fraudsters have a wonderful weekend in a local hotel. Police were called but bank refunded.