Does it matter? The simple reason they are there is to protect my interests. If they can't do it for a few quid, how can they do it for larger sums of money?
The Moral of the Story: Money institutes may not cover you like you think they will.
Some providers are interestingly stubborn when it comes to charge backs and can hold on to the (fraudulent) vendors side even if you're clearly right.
Monzo in the UK is a prime example for that. An internet vendor charged me more than he should and refused to void the transaction (basically text-book fraud) and I filled for a charge back with monzo. I was extremely confident that it wouldn't take much however monzo customer service resisted to help.
The monetary value wasn't much however in the end I perfectly understood that this "protection" does not exist on the credit card issuer/bank side of things.
The Moral of the Story: Money institutes may not cover you like you think they will.
I've learned my lesson.
Again, be -very- careful.