Extension of my contract

So in December 2015 knowing that I was to be billed for the last month following a 2 year terrible contract I have had with Mtn I was advised by my boyfriend whom something similar happened to, to call and tell them my intention of NOT extending my contract I was told by the consultant that she had switched my number to prepaid and that after I'm am debited in December I must call so as to make sure that it was truly done, due to the nature of the inconsistent days that Mtn debits from my accounts after they did so I called on Saturday to make sure if it was cancelled. The consultant mislead me and told me that my contract only expires in January but none the less sent in to request me switching to prepaid had an SMS and and email. Today after having switched my contract to prepaid I get R200 airtime and 300 megabytes loaded into my account after I explicitly specified that I had no intention of prolonging my contract alas the consultant I spoke with told me my contract expired on the 29th December 3015 now she assured me someone would call no one did instead I get a lousy email telling me they will escalate the matter why would I pay R599 for R200 airtime? Highly upset!