For bank of Ireland CC holders, I called the CC enquiry line and they gave the following instructions.
(1) Get email confirmation from hotel that room booking has been canceled
(2) Post hotel cancelation confirmation, purchase receipt from 1800 and a note from yourself authorising the chargeback to address below. (Presume you need to reference your card and date the charge appeared on your statement also???)
bank of ireland chargeback
2nd floor operations centre
cabinteely
dublin 18
No idea how long it will take. I also gave the hotel my sob story and they kindly gave me a discounted rate cheaper than original total. Score....