Overcharged

Morning, I'm Mateboho Ndumo my number is ***, I cancelled my contract in May, ***. The person who was assisting proposed month to month data which will be 20gig, 10 during the day n 10 at night for R129 monthly and I agreed. But I'm suprised when I check my bank statement that Cellc deducted R282,45 instead of R129 as agreed. Please refund me and cancel my contract with immediate effect because this is a reap off. My contact is ***.