Mondeo recording (INCREASE)

So i just sent MTN this email..hopefully now i will get some answers. do not agree this increase UNTIL i have listened to the recording where i Took the contract and the clause was read out to me and I agreed to it. I have called MTN more than twice, i have called Mondeo. I have sent emails to MTN. I am not getting any response with an email address at the store that i can get to!! what else must i do. I do not have time to keep on calling and not being sorted out!!!