False advertising!!!

I booked a place for 4 guests for R700 on air bnb. When I got to the place, the host told me I only booked 1 room for 2 guests. & had to pay extra for other 2 guests to sleep over. So what if I didn't have money to pay for them? Because booking a trip for R700 means I only have that amount to spend. How can my receipt & the listing on air bnb tell me 4 guests for R700 & then afterwards they tell me I had to book both rooms. So when I selected 4 guests why didn't the price change to R1400 because obviously if the host only allows 2 guests in 1 bedroom then where must my other 2 guests sleep??? ****ing ridiculous service. They refuse to refund me. & I suggest nobody books anything with Airbnb. ****ing ****s!