MTN wanna stole my money

I cant believe the way MTN treat there customers.I had data contract cell no.***.Isaw they deducted almaost R300 and suddenly when my contract expired they deducted R1200 from me for 2 months.Why did they not told me about the data expired.Now that i want to close my account they told me that they still gonna deducted R1200 and if I renew my contract ,then I will then be billed with almost R300 with like 150 gig.Why must I pay another R1200.I told them I cancelled my contract.If this is how they treat a client Im tellin them they gonna lose a lot of clients. Im Mr.J H A Smith with id no.*** and my contact phone no. *** thats also an MTN contract.Treat me bad and i will also cancel that contract when it expire.Please people check your expiring contract caus they wont remond you.they will instead of R300 charge you with R1200.Im one very angry and unhappy customer