unhappy

Why this business is lying to their loyal customers, today i went there to find out if i can upgrade my car as per contract. It is almost a year now having the car and they told me i have to cancel the contract and start from scratch. How can they dont read their contract because now they change the tune. later today i got the SMS starting they have made numerous attempts to get in touch with me without success which is totally lying as i did not receive any call from them. Poor office admin and the sales person. i was happy with this contract until today they tell something that i cant understand but is in the agreement contract. My last word is please tell me how many days must i put notice to cancel the contract