Need models for a photoshoot

Hi! I need some help or advice..
I went to an interview for an photoshoot in Canary Wharf. The agency tell me that is free and I did it. When everything finished, they tell me that I had potential so, they offer me an contract. I signed and later they tell me that I need a package because they work with a lot of agencys for represent me. The package was like 5 portraits, 3 agency's to represent me and some jobs, they supposed to take the 25% of every photoshoot that I will do. So I paid 300£ (unfortunately) and later they tell me that some agency's will contact me. I wait and nobody contact me after a few days I call them to cancel my contact and had my money back. And they tell me that is impossible, that them job was really nice and I signed an contract. Then I tell them about my agency or someone to "represent" me. They send me three agency's that each one will charge me 75£ aprox. They principal agency didn't send me the proof of my payment and I just don't want to loose more money on it. And I don't know what can I do, I just don't want this happend to other person.