We have just been informed about a problem that some of our US customers are facing. They bought JuiceDefender Ultimate ($4.99 in the market) but got charged 4.99€ ($6.xx).
This is an issue within the Google Android Market so we can’t do anything; you should contact Google directly: https://checkout.google.com/support/bin/request.py?ctx=cm for Checkout support (might be the best option) or
https://www.google.com/support/androidmarket/bin/request.py?contact_type=market_phone_tablet for Market support.

We have contacted them as well but the chances of getting someone at Google to look into the issue are a lot higher if you contact Google yourself.

We are deeply sorry about the problems caused and hope this can be resolved soon.