Cell C, worst customer service ever.

I have 2 data contracts with cell c, both on a R99 per month for 2 gig contract. Last month my bill increased by 50% without prior warning or notification and this month I received a statement which showed another 50% increase in my monthly payment. I AM SUPER PEEVED. Cell C never communicated this with me and I was never advised that there will be an increase in the monthly amount payable. I found out this morning, after being at a store yesterday to cancel my contracts and being advised I could only cancel via telephone, that my contract had already expired and that it no longer qualifies for the discount? I was never advised that the contract was close to expiry and was not contacted to advise what would happen or how I wish to proceed, but just get a bill with a 200% increase from the amount that I originally signed for. So this morning I asked to have my contracts cancelled WITH IMMEDIATE EFFECT, and I was advised I need to give 30 days notice. This is ridiculous as I was not even given a single day's notice of changes to my contract and I demand that this is dealt with by management ASAP and I be reimbursed for the ******ion!!!