They don't refund rental deposit

I moved out End of January. It all began when the main electricity box was ******. I reported the issue to the flat agent, Miss P, at Indlu Living. Unfortunately, they were unable to fix the problem or find me a new place to stay. I had to go without electricity for a week and a half until the landlord took matters into their own hands and restored power by bypassing cables (not the most honest move). That's when I made the decision to let the Indlu agent know that I would be moving out. The main reason for my departure was the *****ulent activity, as I didn't want to be associated with such behavior. However, the day before I left, they mentioned that I wouldn't be getting a refund on my rent due to short notice. It slipped their mind that I never even signed a lease when I first moved in.