A guest that has manages to change a minimum 2 night booking to 1 night without my consent and has only been charged for one night even though the restrictions on the booking states minimum 2 nights.

A guest made a booking for two nights ( the minimum ) booking for an apartment we rent.

They decided that they only wanted it for one night. They contacted me and asked if they could cancel the second night and I refused.

When I checked the booking the booking had been reduced to 1 night even though the conditions on the booking was minimum 2 nights, it appears booking.com have only taken for one night.

Who is going to pay for the 2nd night ?