Goals Chingford in London

I paid a deposit on a goals ball last week, it was stolen by another customer, I then saw this customer this week and he returned the ball to me. I then returned the ball and asked for my deposit, they wouldn't give me my deposit back and stole the ball out of my hands keeping the ball and my deposit! They claimed it was my fault, the ball had been taken and couldn't return it on the day, they told me I should have told a member of staff that day which I did and he took no action. They were very rude and unpleasant to me and my friends and accused us of lying.