Booking.com refused us any wriggle room despite its cancellation promise

I was planning a family party and was not sure how many hotel rooms we would needI have been charged with planning a family gathering for my father-in-law’s 80th birthday. As a result I used Booking.com to reserve seven refundable rooms at the Copthorne Hotel in Slough, with a view to cancelling any we would not need when the final guest list was confirmed. With this in mind, I was only searching for hotels that offered “free cancellation”, which these clearly did.The next morn