Call the credit card company! They have procedures for this including blocking your credit card and replacing it. You might even be able to get the 40€ back.
There is a lot of articles about this [online][1].

If you knowingly ignore the issue you might be liable for any future damages by fraudulent credit card charges.


  [1]: http://lifehacker.com/what-should-i-do-if-my-credit-card-gets-hacked-1552850022