My MTN contract that been loaded incorrectly since I've taken my contract out and no one can assist me with my cancelation and refund

Please can does someone know what I can do about an contract that is not being loaded correctly since I took out my contract I've been at the branch several times and no one can assist me and called customer services too ..I took out an contract with mtn for 40gig day data and 40gig night express data they are only loading in me 10gig day and 30gig night since I've taken the contract Please can anyone help me