I had the same experience last Friday on an ATM machine belonging to Arab bank. I slotted in my card and entered 11,000 QR and immediately the card came out and the screen didn't give any indication of transaction. No movement of money counting inside the machine and no money came out. I took the card and walked away and after few minutes so received an SMS that my account is debited by the same amount. I called the Doha Bank call center and the guy there told me they will verify with Arab bank and credit it back to my account.
Does anyone have this experience? Am I sure of getting my money back?