Cancellation fee for sim only deal deceiving and abusive

Ordered a Cellc sim only deal which was part of a promotion I was not aware of. This promotion included free delivery. Hidden in the promotion's Terms and Conditions was a cancellation fee of Nine-hundred-ninety-nine rands if cancelling within six months. Seeing as the LTE service in the area was weak the speed is extremely slow. Also hidden in the terms and conditions is that you cannot downgrade your data plan in this "month-to-month" deal for the first six months. It is utterly deceiving and abuses its customers with this policy.