CDISCOUNT ORDER ISSUE

Hello, on Monday, December 17, 2018, around 9 PM, I tried to order a JVC headset for €60.90 on promotion at the displayed price of €29.99. So I placed the order... when it came time to pay, I entered my credit card information (the balance on my card was €30)... and then I saw a message saying that my bank did not authorize me to make this payment... I tried again but got the same message, so I looked at my transaction history and saw -€29 (pending) despite having made only 2 payment attempts, both of which were declined... I then returned to Cdiscount in the "my orders" section and it told me that I had NO ongoing orders... Additionally, I did not even receive an email confirming my order, nor even an order number, probably due to the fact that it was displaying that my bank did not authorize me to make this purchase... I don't understand... Can someone help me?
THANK YOU