A friend of mine rented a room in a house gave a deposit of £600 and the first months rent and stayed there for 8 months paying rent. Gave 2 month notice of moving out. Asked for her deposit back and they said that she had to find someone to move into the room first before she could have her deposit back. So it took a while but she found someone to move in. but they still won't give her the deposit. What can she do as she has no contract as they didn't put her on to the tenecy

What country would this be as from the terminolgy used you clearly are not in the USA or Canada.

Laws vary... so locations matter.

I'm assuming UK, but you may need to narrow it down ad landlord tenant laws are generally more local.

Bottom line is your friend may have to go to court to get her deposit back.