Financial questions that need an answer

Ok:
So I signed a lease with 5 other girls(I was going to share a room with my current roommate and we didn’t the other girls very well) Then, after the lease was signed, the 4 girls had major drama, and really scared me and my roommate, that they were going to break the lease. We found a new place, and told them that we were cool with breaking the lease, and then they told us that they had all prefabricated up.

So we ended up breaking the lease, and they found 2 replacement roommates (therefore we didn’t even pay any rent, nor are entitled to)

Anyways, we did pay $150 for the deposit, and when we broke the lease, I asked one of the girls how we were going to get that back. She reinsured us that the new roommates would pay.

Now, we are on break, and I’ve e-mailed them all about it, but no one has e-mailed me back.

How do I get my money back? Any suggestions?