Not willing to assist- all they say there’s nothing we can do

Yhoooo - I made a mistake with my booking - I asked them to change my booking- they kept giving me numbers to call until they blocked my numbers- They told me there’s nothing they can do I must just rebook - no refund not amendments nothing- I have lost that money for booking-The booking haven’t even come yet- they can still sell or rent it out the room to someone else- but they were not willing to assist- until they blocked my calls - wowww