Not living up to guarantees and expectations

this company has drived me crazy, promise response within 24 hours, not delivered, promises study material in 5 -7 working days, not delivered, assignments to be marked in a week, not delivered, and that extra study timd they promise they only add it to the end of your studies, O and when you cancel the amount they quoted suddenly changes and you have to pay a huge amount to cancel, I am so duscusted, I enrolled and paid 1500 per month which is expensive, and when i now canceled they say I must pay them +/- 8000, and that my course total is 58000 instead of the 43000 they quoted me in the beginning