Incorrect Charge on My QNB Finansbank Card After Canceling Booking Reservation

I made a hotel reservation in Greece through Booking.com on August 2nd using my QNB Finansbank credit card. The reservation had an option for free cancellation, so I canceled it afterward. Despite this, I noticed that 123 euros were charged to my card instead of the expected 83 euros. When I contacted my bank to clarify the issue, they said they couldn't retrieve any detailed information regarding the charge. I've tried reaching out to the hotel via Booking.com, but I'm still unsure how to resolve this or get my money back. Additionally, my bank can’t access the transaction details, including the authorization code, making it impossible to reverse the charge. My confirmation number is 4811.242.619. I need assistance in recovering the overcharged amount.