How to get my parents to buy me clothes?

I am a 15 year old girl and my parents never buy me clothes. I also have a younger sister( she's 10). Money isnt a problem, we are not rich but my parents make decent money. My parents HATE shopping and never give me or my sister money to buy new clothes. I DO have clothes but they are all very, very old (like from 5 and 6 years ago) and are ratty and small. We only go shopping at the beginning of school and maybe summer and my parents give us like $50 each to buy clothes. I get $15 a week for an allowance, but i have to buy the things i need too (lunch money, pens/pencils/ socks etc.) so i can never save up any money. Its come to the point where i do my laundry and can only wear the same couple of shirts and pants because i have no other clothes. We go to the mall sometimes and my dad will buy jeans at bluenotes or shoes for himself and he never buys us anything. I absolutely never go shopping because i have no money. Also, my parents dont pay me for chores (other then allowance) and im not allowed to get a job. What should i do?!?