MTN Mondo bad services!!!!

I have been trying to cancel my contract for the past 9 months with no luck!!! When I made the contract with them they told me I would get R120 airtime and 12GB data per month for R89.00 I was very excited about the offer hence I continued with it only to find out that the offer was valid for the first month of my contract only, I am only getting R120 airtime that I can't even buy data with it is actually airtime converted to R120 minutes. I went to Mtn stores they told me they don't deal with cancellations, I have tried phoning them several times but what they do best is giving out false information or transferring, I promise you they will transfer you from one department to another!! I have sent the email here(***) they just send you an automatic response giving you a reference number and letting you know that the call centre agent will contact you even today I am. I phoned them to ask how much am I owing and that I want to cancel the contract they told me I should pay R480 that I owe only then will they be able to assist cancelling my contract I did even sent a proof of payment, I phoned again to inform them about my payment so that they can now cancel that contract, they then told me there is R90.00 that is due again I went to pay them ,when I called again today to inform them about my second payment and to ask them to cancel my contract only now they are telling me about a cancellation fee I mean why didn't they tell me from the first place that I have to pay the money I owed and cancellation fee and give the whole amount what is this back and forth for? why should this agents be nice only when they offer you a contract but rude when you want to cancel it, I HOPE THIS TIME MY MATTER WILL BE TAKEN SERIOUSLY!!!!! I WANT OUT