why does apple charge me for just linking my debit card to my apple account (twice with 3.96 Euros)?

Hello,

I moved from Hong Kong to Spain last month and set up a new apple account for my new bank account in Spain, at first while I linking the card it always got declined then when I finally linked it up it charged me 1.98 euros but still not working (can't even download apps), then I thought maybe there was something going wrong so I submit my debit card information again to my apple account however it charged me another 1,98 euros. I though apple only want to make sure I have enough balance but now I am really confused.

Vivienne