A: If Booking.com promised you twin beds, then it should have delivered twin beds. End of story.
But did it? I visited the site to make a dummy reservation at Adagio Paris Bercy Village. When you click on the studio, it clearly says: “Please note that the double bed in this studio is a fold-down bed in the living area. Two twin beds are available upon request.” So you would have needed to get a written assurance from the property or from Booking.com that your studio came with twin beds.
Cases like yours underscore the importance of reading your product description and confirmation carefully. If you have any questions, get the answers in writing, not by phone.
If I read the property description, I probably would not come away with the impression that I’d get two twin beds. But you say you had a confirmation that you would — and hey, I’m your advocate.
Based on the correspondence you’ve sent me, it appears as if Booking.com was willing to help cancel your reservation, but that you would have to pay a fee. You might have appealed this to an executive at Booking.com (http://elliott.org/company-contacts/booking-com/) or at Priceline Group, which owns Booking.com (http://elliott.org/company-contacts/priceline/).
Cases like yours underscore the importance of reading your product description and confirmation carefully. If you have any questions, get the answers in writing, not by phone. Otherwise, you could find yourself in a room with a wrong-size bed.
In the end, I believe you were left with the impression that you would get twin beds, and leaving you with the right impression is the company’s responsibility. I contacted Booking.com on your behalf. Booking.com contacted the hotel, which agreed to a refund with no cancellation fee. Enjoy Paris.