people can be so rude!!

Just when i thought I had settled my apartment- another thing smacks me in the face.
We had contacted 3 boys and asked if they wanted to take over our lease (a 3 bedroom apartment)
it was close to the school they would be going
we offered them a ton of furniture for very low prices, 
offered that they only had to pay half rent their first month in.

and now just because of one little stain in my bedroom they want us to pay him $700 to have the carpets in ALL of the rooms replaced. 
he already owed us the half-rent and the furniture.
he said if we don't pay him, he won't take the furniture or the apartment. and unfortunately- that would be so much more expensive to try and pay (two months of rent along with trying to sell furniture from far, and all that.) 

both of my roommates don't have the money right now, so we had to brunt the full cost and they will pay be back over time. 

I'm just so f**ing stressed and pissed off to tears about this.