Unhappy service from Booking.com

I booked on booking.com for 3 nights , I traveled from far with luggage,I arrived at 14:30 as per check in time ,I couldn’t get ahold of the host which led to me waiting at a shopping center whilst it was raining ,I’ve been trying to get ahold of the host and they told me they have guests at the apartment after I’ve paid 4,8K ,the host has been ignoring my calls and I later had to booking into another accomodation which was an accumulation of costs ,this is highly unacceptable as I couldn’t get my moneys worth ,I’m highly disappointed in the level of professionalism they provided. I am not happy