****med by Mtn

My contract with Mtn was about to expire and was called to renew it but with different number of data bundles. I was receiving 40 gigs on the expired contact. 20 day and 20 night. So they told me that on the renewed contract I will get 80 gig. 40 day 40 night. To my surprise I still get 40 gig 20 day 20 night. Was I ****med by Mtn? How do I cancel this contract because they are not keeping to the end of the bargain that was even suggested by them. The contract number is ***