Is there a situation where an e-shop can block your money? Yes, there is.
Using what is known as a pre-authorised payment, the merchant can block the amount for the ordered goods on your account. You will most often come across a payment block in these cases:
e-shops with fluctuating stock levels
hotels
car rentals
subscriptions
other online services
A payment block means the amount is temporarily blocked on your account. The amount can be blocked for a maximum of 4 days. After that the merchant either captures the money or releases it.
When the payment is captured, the amount is debited from your bank account and you receive the goods or service you paid for.
When the payment is released, the amount is not debited from your account and stays there. You do not receive the goods or service.