A 25 month contract???

I opened up a contract at vodacom stores during June 2014. Debit orders came off from the start of the contract. I called vodacom during January saying that I want to cancel contract. I was told too early to do so but could call inat 2016 to cancel my contract. I was told it csn be cancelled in May and my last debit order will be during May. So at the start of May I now want to cancel and I am told my last debit order will be End of June. Hoe csn this be so? I've even had the phone pit down by a calll centre consultation. I want this cancelled and moved to prepaid. Call me to dis cuss, seems social media cimplants are the only place ehere this gets addressed. I even have the email as proof that vodacom employee confirmed this .