Thank you for the reply, pb9997! To be clear, the part paid with points was more like 75% of the full rate, but you are probably right in that I should have requested at least a full refund. I fully agree with you that while shiny and nice on the outside, the Mama Shelter Prague failed to deliver on the basic requirements of a hotel. Judging from the Tripadvisor reviews it seems like they have straightened out most of the teething issues by now (they also seem to have decreased the rates by quite a bit now, but that might also be that demand for hotels go down in winter in Prague).

Do you have any suggestions for how to proceed with this, given that neither Accor Customer Care nor the hotel seems to be willing to help?