Hey, You can find the Air China Sales Office in London at 389 Chiswick High Road, West Wing, on the 11th Floor. It provides services such as reserving tickets, altering flights, and offering general travel help. The personnel are supportive and offer rapid assistance for customer requirements. For on-site assistance, you can also go to their office at Heathrow Airport in Terminal 2. For customer support, they are accessible around the clock. For questions, you can contact them.