I'm sorry for your experience. However, thank you for mentioned that the communication was good! As a responsible host, we'd hope to hear from you earlier during the stay so that we can easily fix things like pillows (we have a good supply of all kinds of pillows) and bed.
Regarding the wifi, another guest Keelan Long, mentioned it's fast in the review of the other room in the same apartment: "Everything is as pictured, the unit has two bedrooms and the other one was rented to another Airbnb guest who was going to the same conference I was so that was fun. Internet was stable and decently fast (about 20Mbit down)." Keelan stayed in the other room in the same period of time, and I hope the information helps to explain the correct speed we had.