@Jasper00
Can you not just take your bid off? like remove it?
Go into your account and just click 'remove bid!'
Should be able to do that. 
I have heard of this happen before. My friend bid on a property in a nice area, but it showed a pic of one that had a field and some woods behind. It was around 200 feet (70 metres,) from the main road/high street. Perfect for the kids and the dog.
She had a tootle around the area, and loved it. She bid on the house, and was No 1 and was offered it. She accepted it (provisionally/ verbally, so didn't sign the tenancy agreement at this point.)
Come a week later she was offered the chance to view it, and it was one up the road, 15 houses away. Pretty much the same property, but in a different place, and only 30-40 feet from the main road/high street. (12-13 yards.) The side garden was big (as it was the first one on the cul de sac of 32 homes,) but still, it was not the house she was lead to believe it was IYSWIM.
If you have already had an offer and accepted, maybe appeal to the housing officer's better nature and say you thought it was a different house and you were somewhat mislead, and you would like to withdraw your offer. And ask them to not hold it against you.
Not sure what will happen as all councils and housing associations are different, But it's worth a shot.
Great idea to screenshot the house by the way, to prove they were promoting a different one. Probably the only way that some of the councils can get houses let, in 'hard-to-let' areas, by conning people!
I am really puzzled at Band 4 people being offered homes over and above Band 1 by the way. What's THAT about? They should not even be a priority at all compared to people in the top band surely?
My friend accepted the house nearer to the main road by the way, as the more she looked at it and thought about it, the more she wanted it (coz of the huge garden,) and the high street wasn't too busy. (The pic of the other house was used by the way, because they didn't have time to come out to take a pic of the house my friend bid on, and the houses were both the same... it wasn't a hard-to-let area, so they were probably telling the truth.)
5 years on she is still there, and very happy. 
Not sure you will be though. 
All the best. 