Quit my job!!

I couldn't believe what they've done to me theres another pregannt woman working at the hair and beauty salon That i work in and she's only 3 months im 5 and they let her take more breaks to eat and they don't make her do a lot and she finishes work early, with me on the other hand they only give me one break and if I go to eat for 2 seconds if I get hungry they moan and they made me get on my knees and scrub the floor like this is some fairy tale and they all sit down in the kitchen when there's no clients and make me Stand at front desk to watch the front when I should be resting every chance I get and because I'm a junior at hairdressing she said she won't pay me for One of the days that I work not only that she's paying me less then minimum wage I work 10 hours and get paid 30 a day which means 3 pound an hour I couldn't take the stress had to quick ??