Call. Discuss this with a manager. Then send that person an email confirming and call again on the morning of your arrival.

When you ask, explain what you want so that you don't get into semantic arguments.

This advice about speaking with another human being avoids many of the problems which people report on FT. Believe it or not, many people in the hospitality industry really do want to be hospitable. When you make a connection with someone, they are more likely to help you. Nothing is ever certain, but this goes a long way.