Timings???

i hav started my articleship this august. i entered into articleship agreement 4 3 years. as per agreement i agreed for the timings 10 to 7. but later its becoming a hectic.i too got to know that timings r only 35 hrs a weel that is just 5 hrs a day n m working 9 hours ...hell... i asked my principal to change it to 6 atleast  but he is adamant abt that...what do i do????