"I rang on the wednesday to..."

I rang on the wednesday to view the property, the lady i spoke to said she would ring the lady doing the viewings and get back to me. she didnt get back to me by the end off the day so i rang and spoke to a different lady. she informed to just go to the viewing the next day at 6.15. i arrived there the next day after arranging child care, to find out that the house had already been taken. The lady at the house said she rang belvoir on the thursday to confirm she is ok with the viewing, for them to inform her that someone has applied already. the lady at the address was very nice and apologised. I rang bevoir today and the lady i spoke to was very rude on the phone and when i was explaining, she interupted very rudely saying, my details where not on the list and there is nothing i can do till i speak to the lady who you contacted, who is on holiday.