Just a few minutes ago I found out I was tricked/robbed for the first time, so I'm pretty angry.

I thought it would be a good idea to centralize these kind of experience, in order to learn from each other and avoid bad experiences in the future, if possible.
My bad experience probably comes from lack of previous experience with ordering online. Last month I made my first order through Amazon (I normally buy in shops). They had this customer program through which you don't pay for shipping in the first month, so I subscribed to it.
What they didn't say and I didn't think I should check further was that after that first month it's not like y
ou pay for every shipping you need for your orders, but you pay
a 50 euro monthly fee which they automatically take from your bank account without asking you, regardless whether you place new orders or not.

I only found about this important detail when I noticed the payment of the first monthly fee.
Probably most of you people who buy regularly on the Internet know about this and take precautions, but I hope this still may be of help for someone.