I got the same shocker last week at Media Markt when I wanted to pay with my credit card for a 600.-chf camera there. Fortunately I was able to pay with the Maestro Card. The problem with the Maestro is that they often have a very low limit (I think 1000.- or 2000.- chf per purchase) which isn't going to do you much good buying some of the big ticket items that Media Markt carries.