Ad not specifying sofa bed as 3rd bed [AUS]

Hi everyone! Just after some advice, I have had an air bnb booked a month in advance, the ad states that 4 beds are available and 3 bedrooms, 1 bedroom having two twins. Now I have just received a message from the host asking what bed configuration I would prefer, he mentions that one bed is a sofa bed. The ad did not specify that one bed would be a pull out, it is in a seperate room but I am paying over $1300 for a 4 night stay and expected there to be proper beds. Should I mention this to the host? If I had of known I wouldn’t have booked this place I’m pretty disappointed as I know sofa beds are no where near as comfortable and will have 2 people sleeping on it.