can i claim back credit card charges?

claim them for what? to pay them, sure? as some sort of deduction, no.

From all that I have heard ,you certainly can.I think there are even websites that can help you with this.When I have been charged in the past I often found a friendly phone call and they will waver the charge.If this does not work,tell them you think you will have to cancel your card.I did that once and they dropped the charges immediately.