cancellation of contract

i was assisted by Kelly who signed me up and explained everything except for the contract term of 36 months. i sms'd him the next day as he had provided his cellphone number but never got a response. i couldnt even find out how to cancel this contract as the person who signed me up decided to ignore me. i want to cancel this contract as it wont work for me. Membership no.08300 i am not happy that there isnt transparecy and they dont give you all the information they just rush to sign you up.